Noteworthy Feats

These are published feats. I'm listing them because there are so many, we will inevitably forget them.

General
Adaptable Flanker (PHB2) - Choose to occupy one additional square you threaten for the purposes of flanking.
Clever Opportunist (Drow of the Underdark) - If you hit with an AOO, you can swap places with the target. 

Close Quarters Fighting (Draconomicon) - You can AOO enemies using improved grab-type attacks.

Coercive Spell (Drow of the Underdark) - +1 Metamagic. Enemies damaged by this spell have -3 on Will saves.
Constant Guardian (Drow of the Underdark) - Take -2 on attacks to grant an ally +2 on AC.

Danger Sense (Miniatures Handbook) - Once per day, reroll your initiative.
Dash (Miniatures Handbook) - This should be a prereq for Swift Steps.
Deafening Spell (Drow of the Underdark) - +1 Metamagic. Enemies damaged by your spell are deafened.

Death Blow (Complete Adventurer) - Coup de grace is a standard action for you.
Deft Opportunist (Complete Adventurer) - +4 attack bonus when making AOOs.
Delay Potion (Complete Mage) - You can delay a potion's effect for hours, then activate whenever you please.

Double Hit (Miniatures Handbook) - You may swing with both weapons during an AOO.
Draconic Resistance (Complete Arcane) - Gain resistance to your draconic heritage attack type.
Draconic Skin (Complete Arcane) - Gain natural armor +1.
Dutiful Guardian (Drow of the Underdark) - You can swap places with the target of Constant Guardian.

Dwarf's Toughness (Masters of the Wild) - If you have a base fort save of +5, this gives twice as much HP as toughness.
Energy Abjuration (Complete Mage) - Get energy resistance when you cast abjuration spells.

Eschew Materials (Complete Arcane) - You don't need a component pouch.
Expert Tactician (Complete Adventurer) - You and allies gain +2 to hit and damage against enemies you strike with AOOs.
Grenadier (PHB2) - Increases damage and accuracy of grenadelike weapons.
Healing Devotion (Complete Champion) - Fast healing 2, once per day for one minute.
Hold the Line (Complete Warrior) - You can AOO enemies who charge into your threatened space.

Improved Flight (Complete Adventurer) - Your flight maneuverability increases.
Improved Toughness (Monster Manual 4) - Gain 1HP per hit die. Probably not stackable.
Indomitable Soul (PHB2) - Roll twice to save versus mind-affecting spells.
Insightful Divination (Complete Mage) - If you cast a divination, bonus on init checks for 24 hours.

Knock Down (Sword and Fist) - If you deal 10 damage or more, you get a free trip attempt.
Magic Disruption (Complete Mage) - Immediate action softening of incoming spells if you have a dispel ready.
Magic Sensitive (Complete Mage) - If you have a divination available, you automatically sense nearby magic.
Master of Poisons (Drow of the Underdark) - You cannot poison yourself accidentally.
Poisoned Spell (Drow of the Underdark) - You can add poison as a material component to a damaging spell.

Powerful Charge/Greater - You do extra damage on charge attacks.
Practiced Spellcaster - Your caster level increases by 4, to a maximum of 6.
Quick Recovery (Lords of Madness) - You get an extra save against stun and daze effects on your turn.
Rapid Metamagic (Complete Mage) - This needs to be available in e6.

Reach Spell (Complete Divine) - Metamagic: Cast a touch spell at short range.

Silver Blood (Champions of Valor) - You cannot be turned into a werecreature.
Strong Stomach (Cityscape) - Nauseation effects sicken you, sickening effects do nothing.
Subduing Strike (Exalted Deeds) - You can deal nonlethal damage without penalty.
Two-Weapon Pounce - You can charge and dual strike.
Vengeful Surge (Fiendish Codex 2) - If you successfully save against an effect, you deal double damage to the owner of the effect for 1 round.
Wild Talent (Expanded Psionics Handbook) - You become an esper and can take psionic feats.

Bard
Alluring (Song and Silence) - +save DC of mind-altering spells. Reqs skill feats.
Appraise Magic Value (Complete Adventurer) - Cheaper identify.
Arcane Accompaniment (PHB2) - Expend a spell slot to extend the duration of a song. Most useful for fascination or other mezzes.
Arcane Defense (Complete Arcane) - +3 to save from a spell focused school.
Arcane Mastery (Complete Arcane) -  You can take 10 on caster level checks.
Assume Supernatural Ability (Savage Species) - Get one (Su) ability of something you morph into.
Battle Caster (Complete Arcane) - Cast effectively in medium armor.
Battle Dancer (PHB2) - Gives a +2 morale bonus on attacks if you move; technically this shouldn't stack but it's clearly supposed to.
Captivating Melody (Complete Mage) - Spend music to increase save DC of illusion or enchantment by 2.

Charm Immunity/Resistance (Serpent Kingdoms) - Resistance or immunity to charm powers. Not super useful, since charm person doesn't affect fey, but...
Chant of Fortitude (Complete Adventurer) - Bardsong. Immediate action. All allies get the Diehard feat.
Collector of Stories (Complete Scoundrel) - +5 bonus on KS checks to find monster properties.
Conceal Spellcasting (Complete Scoundrel) - Sleight of Hand can be used to conceal spells, too.

Crossbow Sniper (PHB2) - Gives Dex bonus to damage with crossbows.
Daunting Presence (Miniatures Handbook) - 30ft ranged intimidate (uses 1/2 character level)
Dimensional Reach (Complete Mage) - Teleport unattended items to you as a standard action.

Disguise Spell (Complete Adventurer) - You can disguise spells you cast as performances.
Distracting Attack (Miniatures Handbook) - If you melee an enemy at all, everyone else attacking it gets +1.
Doomspeak (Champions of Ruin) - Bardsong; massively debuff a single enemy.
Elf Dilettante (Races of Wild) - Jack of All Trades with +1 bonus for elves only.
Elven Spell Lore (one of the Faerun books @.@) - +2 bonus on dispel checks.
Enchanting Song (Races of Stone) - +1 to save DC of an enchantment spell by spending a music use.
Epic of the Lost King (Complete Scoundrel) - Bardsong; remove fatigue from up to three allies.

Extra Music (Complete Adventurer) - +4 music uses.
Face-Changer (Complete Mage) - Disguise self as a reserve feat.
False Theurgy (Complete Scoundrel) - Your spellcasting cannot be countered without dispels.

Fey Heritage tree (Complete Mage) - If I get bored, +1 on enchantment spells I guess is good

Focused Mind (Races of Wild) - +2 to any Int-related check if you take 10 or 20.
Force of Personality (Complete Adventurer) - Use Cha modifier for Will saves instead of Wis.
Haunting Melody (Heroes of Horror) - Bardsong. Shakes enemies.
Insightful Reflexes (Complete Adventurer) - Use Int modifier for Reflex saves instead of Dex.
Inspire Spellpower (Races of Stone) - Bardsong, +1 to CL of all casting allies (not to you)
Kiai Shout (Complete Warrior) - 30ft area intimidate.

Lingering Song (Complete Adventurer) - Bardsongs last for 1 minute.
Lyric Spell (Complete Adventurer) - Spend bardic music to cast spells.
Magic Device Attunement (Complete Mage) - You only have to check UMD once on a device every 24 hours.

Master Manipulator (I don't remember) - You can talk to penalize other people's perception checks. You also can catch an enemy in a lie and find the purpose behind it.
Master of Knowledge (Heroes of Horror) - +1 to all KS.
Melodic Casting (Complete Mage) - Screw concentration, I have perform!

Metamagic Song (Races of Stone) - Just what I've always wanted!
Mobile Spellcasting (Complete Adventurer) - You can move and cast with a single standard action.
Netherese Battle Curse (Lost Empires of Faerun) - You can spend a spell to debuff enemies with a melee attack.
Nonverbal Spell (Planar Handbook) - You can substitute anything for the verbal component of a spell.
Obscure Lore (Complete Adventurer) - +4 on bardlore.
Obtain Familiar (Complete Arcane) - Get a familiar.
Psychoanalyst (Psionics Handbook 3.0) - +2 on most social/Cha-related checks.
Sound of Silence (Complete Scoundrel) - This is really bad but its a good benchmark for something good.

Subsonics (Complete Adventurer) - Your bardsongs do not have to make noise.
Touch of Distraction (Complete Mage) - You're only taking this for +1 CL to enchantment.

Touch of Healing (Complete Champion) - You can soft heal allies up to half their maximum HP.
Trickery Devotion (Complete Champion) - You can create an illusionary clone of yourself to fool enemies.

Trivial Knowledge (Races of Stone) - Roll twice and use the better on KS/bardlore checks.
Unsettling Enchantment (Complete Mage) - Foes subjected to your enchantment spells get -2 AC and attack for 1 round, even if they make their save.

Versatile Performer (Complete Adventurer) - Level multiple perform skills and get +2 on combined perform checks.
Versatile Spellcaster (Races of Dragon) - Spend 2 lower-level slots to cast a higher level spell.
Warning Shout (Complete Scoundrel) - Bardsong, grants +5 reflex and evasion. 2 uses; too expensive?

Windsinger (Stormwrack) - Calm the winds of the sea with bardsongs.
Words of Creation (Exalted Deeds) - Take nonlethal damage to improve bardsong powers.

Cleric
Agile Shield Fighter (PHB2) - Two-Weapon Fighting for shields only. No Dex requirement!

Awesome Smite (Complete Champion) - Several tactical maneuvers for smite attacks.
Augment Healing (Complete Divine) - +2 healing per spell level to every heal you cast.

Bane of Infidels (Power of Faerun) - You gain a favored enemy of your deity. 

Celestial Bloodline (Races of Faerun) - You get protection from evil and bless as spell-like abilities.
Cometary Collision (PHB2) - Allows you to counter-charge anyone charging your allies. 

Destruction Devotion (Complete Champion) - You can lower your enemy's armor bonus with your attacks.
Disciple of the Sun (Complete Divine) - Spend 2 turning attempts to destroy undead instead of turning them.

Divine Armor (PHB2) - Swift action to gain DR5 until your next turn.
Divine Defiance (Fiendish Codex 2) - Immediate, turning - You may counter as though you've readied.
Divine Metamagic (Complete Divine) - Win the game.
Divine Shield (Complete Warrior) - Standard: spend turn, add your Cha mod to your shield AC for 3 rounds.

Divine Spell Power (Complete Divine) - Free: spend turn, boost the caster level of a spell.

Divine Ward (PHB2) - You can spend daily turnings to cast touch-range spells at short range on a warded ally.
Divine Vigor (Complete Warrior) - Standard, turning: +10 movespeed and +12 temporary hitpoints.

Empower Turning (Complete Divine) - You deal 50% more turning damage.

Exalted Turning (Exalted Deeds) - Undead you turn get nuked for big damage.
Extra Domain Spell - You can cast a single domain spell an extra time per day.
Extra Smiting (Complete Warrior) - You get two additional daily smites.

Eyes of Light (Races of Faerun) - You can fire searing light from your eyes instead of your daylight racial.
Fire Devotion (Complete Champion) - You can make your melee attacks light enemies on fire.
Focused Shield (Races of Stone) - When psionically focused, +1 to shield AC.
Healing Hands (Complete Scoundrel) - First aid heals the target for 1d6 hp.

Heavy Armor Optimization (Races of Stone) - +1 to heavy armor AC, -1 to armor check penalty.
Imbued Healing (Complete Champion) - Grant buffs to allies when you heal them.
Improved Smiting (Complete Divine) - Your smite rapes evil creatures in the face.

Inured to Energy (Savage Species) - +10 to racial elemental resistance.
Mitigate Suffering (Complete Champion) - You can restore damaged abilities temporarily.

Outsider Wings (Races of Faerun) - You get wings and can fly.
Parrying Shield (Lords of Madness) - You get your shield AC as touch AC.
Persistent Refusal (Fiendish Codex 2) - Swift, turning - Gain another save attempt against an effect you are currently debuffed with. 
Quicken Turning (Complete Divine) - Turning is a free action.

Retrieve Spell (Complete Champion) - You can recover an already cast spell by using turning powers.
Sacred Healing (Complete Divine) - Grant fast healing 3 as a full-round action to all nearby living creatures.

Sanctify Water (Stormwrack) - Spend turning to turn all water near you holy for a short period.
Sacred Purification (PHB2) - Swift, spend turn: Heal all living creatures in 60ft spread for d8+cha, damage undead for same.
Shielded Casting (Races of Stone) - Cast spells without provoking if you've got a shield. Wow.
Shieldmate/Improved Shieldmate (Miniatures Handbook) - Adjacent allies get +AC when you have a shield.
Shield Specialization (PHB2) - Gives +1 to shield AC, required for Agile Shield Fighter.
Shield Ward (PHB2) - Get your shield AC as touch AC (same as Parrying Shield).
Somatic Weaponry (Complete Mage) - My sword is my somatic component, bitch.

Spiritual Counter (Complete Champion) - You may spend turning attempts to counterspell.
Spontaneous Domains (Complete Champion) - You may select your domain spells as you need them.
Spontaneous Wounder (Complete Divine) - You can spontaneously inflict.

Spurn Death's Touch (Libris Mortis) - This is basically the resto feat, available at level 1.
Touch of Healing (Complete Champion) - You can soft heal allies up to half their maximum HP.


Fighter
Allied Defense (Shining South) - Adjacent allies get your AC bonus from Combat Expertise.
Deadly Defense (Complete Scoundrel) - When taking -2 from Combat Expertise, light weapons deal +1d6 damage.
Deep Impact (Expanded Psionics Handbook) - Expend psionic focus; resolve an attack as a melee touch attack.

Dual Strike (Complete Adventurer) - Attack with both weapons at the same target as a standard action.
Efficient Defender (Cityscape) - Light armor is +1 AC, but armor check penalty increases by 1.
Improved Buckler Defense (Complete Warrior) - You can parry with a buckler while you TWF.

Mage Slayer (Complete Arcane) - Spellcasters within reach cannot cast defensively against you.
Natural Bully (Heroes of Ruin) - Enemies with less than half your HD are afraid of you, suffer penalties.
Never Outnumbered (Complete Scoundrel) - Intimidate becomes a PBAoE with 10ft radius.
Nimble Stand (Complete Scoundrel) - You can get up from prone without provoking an AOO.

Off-Hand Parry (Masters of the Wild) - On a full attack, +2 dodge bonus to AC and gain any shield bonus from a buckler if you forgo your offhand swings. You take the TWF penalties to hit.
Oversized Two-Weapon Fighting (Complete Adventurer) - You may wield any one-handed weapon in your off-hand as though it was a light weapon.
Pierce Magical Concealment (Complete Arcane) - You can hit invisible, blurred, and blinking enemies.
Pierce Magical Protection (Complete Arcane) - Mage armor don't mean shit to you.
Power Critical (Complete Warrior) - You are +4 on crit confirms.
Prone Attack (Complete Warrior) - You can attack while prone. If you hit, you can stand as a free action. Opponents don't get a bonus to hit you while prone.
Psionic Body (Expanded Psionics Handbook) - +2 HP per psionic feat.

Resounding Blow (Exalted Deeds) - When you score a crit, it forces the enemy to save or cower.
Sidestep (Miniatures Handbook) - If you make an AOO, once per round you can take an extra 5-foot step.
Speed of Thougt (Expanded Psionics Handbook) - When psionically focused, you move at +10 feet.
Tome of Battle (the whole book) - not gonna go into everything in this book that Kaeli should want

Ranger
Animal Friend (Exalted Deeds) - You can tame magical beasts.
Ascetic Hunter (Complete Adventurer) - Ranger levels become monk levels for fist damage, favored enemy bonus added to save DC for stunning fist.
Blazing Berserker (Sandstorm) - While raging, you gain the fire subtype.
Circle Kick (Sword and Fist) - Hit two enemies with one unarmed attack.
Cometary Collision (PHB2) - Allows you to counter-charge anyone charging your allies.
Companion Spellbound (PHB2) - Companion shares spells at 30ft, and you can touch your companion at short range.
Coordinated Strike (Races of Wild) - +1 bonus if both you and pet attack the same enemy.
Curling Wave Strike (Stormwrack) - Trip-cleave.
Darkstalker (Lords of Madness) - You can hide versus creatures with blindsight, tremorsense, and scent.
Deft Opportunist (Miniatures Handbook) - +4 on AOOs.
Exalted Companion (Exalted Deeds) - An exalted animal companion is freaking OP.
Extra Favored Enemy (Masters of the Wild) - You get an extra favored enemy.
Favored Critical (Masters of the Wild) - Pick a favored enemy; you get Improved Critical on them.
Fist of the Heavens (Exalted Deeds) - Increases the save DC on stunning fist versus evil enemies.
Greenbound Summoning (Lost Empires of Faerun) - Any nature creatures you summon gain the greenbound template.
Hazing Strike (Secrets of Sarlona) - A successful stunning fist also ends any nonmagical altered combat state, including rage, combat focus, psionic focus, etc.
Improved Favored Enemy (Complete Warrior) - You deal +3 damage to ALL favored enemies.

Improved Natural Attack (Monster Manual 3) - Improves your natural weapon by 1 step.
Large and In Charge (Sword and Fist) - While enlarged, you can knock enemies back if you hit them with your AOOs.
Mad Foam Rager (PHB2) - You can delay the effects of one spell or attack by 1 round if you are raged.
Mage Slayer (Miniatures Handbook) - +1 on will saves; enemies you threaten may not cast defensively.
Martial Throw (Miniatures Handbook) - You can swap places with an enemy if you hit with an unarmed strike.
Natural Bond (Complete Adventurer) - +3 effective druid level for your animal companion.
Nemesis (Exalted Deeds) - You get radar sense for a favored enemy and +1d6 when damaging evil ones.
Pharaoh's Fist (Sandstorm) - AoE stunning fist.
Quick Reconnoiter - You automatically make perception checks as though you were actively searching.
Reckless Rage (Races of Stone) - Extra -2 to AC and +2 to Str/Con while raging.
Roundabout Kick (Complete Warrior) - If you crit with an unarmed strike, you can attack again.

Short Haft (PHB2) - You can shorten the grip of a reach weapon to attack adjacent enemies.
Snap Kick (Tome of Battle) - Get an extra unarmed attack on any attack action.
Snatch (Masters of the Wild) - You get improved grab with your natural weapons.
Spinning Halberd (Complete Warrior) - This is not as good as Snap Kick, so if you're forced to choose, get the kick instead. If you can use both, get both.
Stand Still (Expanded Psionics Handbook) - You can halt an enemy instead of dealing damage with an AOO.

Sun School (Complete Warrior) - An interesting, if mediocre unarmed attack style.

Superior Unarmed Strike (Tome of Battle) - Unarmed strike damage becomes better.

Sorcerer
Arcane Defense (Complete Arcane) - +3 to save from a spell focused school.
Arcane Disciple (Complete Divine) - You can cast spells from a specified cleric domain.

Arcane Thesis (PHB2) - For both arcane casters, this adds CL to any single spell and reduces metamagic application cost. SCORCHING RAY!
Arcane Mastery (Complete Arcane) -  You can take 10 on caster level checks.
Bane Magic (Heroes of Horror) - Your spells do extra damage to a specific creature type.
Beckon the Frozen (Frostburn) - You can summon frostfell creatures (may want to petition Nick for fire subtype creatures if that's your thing).
Blade of Force (Complete Mage) - You get +1 CL to force spells and can enhance ally weapons with force damage as a swift action.

Blistering Spell (PHB2) - +2 points of fire damage per spell level and penalty on rolls and checks. Only really good if Nick allows it as a Sudden feat, or if Nick gives a wand or rod with the feat. It's still good for scorching ray, though.
Combat Familiar (PHB2) - Familiar doesn't provoke AOO for entering enemy squares if it is holding a touch charge.
Draconic Flight (Complete Arcane) - You can fly any time you cast a standard action spell.
Draconic Power (Complete Arcane) - +1 caster level for spells that match your energy type.
Draconic Presence (Complete Arcane) - When you cast a spell, you make enemies afraid of you.
Energy Substitution (Complete Arcane) - You can make your energy attack spells a different energy type.
Fiery Burst (Complete Mage) - This feat ruins the game.

Force of Personality (Complete Adventurer) - Use Cha modifier for Will saves instead of Wis.
Invisible Needle (Complete Mage) - Another +1 to force spells and free force bolt attack.

Invisible Spell (Cityscape) - Metamagic +0(!) Your spell's visual effect is invisible.
Lurking Familiar (PHB2) - Your familiar can hide if it occupies the same space as you.
Metamagic Spell Focus (Complete Mage) - Metamagic feats applied to your specialized school cost 1 less spell level. 3 daily uses.

Mobile Spellcasting (Complete Adventurer) - You can move and cast with a single standard action.
Planar Familiar (Planar Handbook) - Your familiar becomes aligned to either law or chaos.
Purify Spell (Exalted Deeds) - A nuke you deliver deals no damage to good creatures and bonus to evil.
Ranged Spell Specialization (Complete Arcane) - +2 damage on ranged touch attack spells like rays.
Sculpt Spell (Cityscape, possibly others) - Metamagic +1, can alter the area of an area spell
Selective Spell (Shining South) - Metamagic +1, can select one ally to be excluded from the AoE of your spell.
Spell Thematics (Magic of Faerun) - Your spells have a "style" and your spells are harder to counter.
Storm Bolt (Complete Mage) - An alternative for Fiery Burst. Not quite as good, because fire is better.

Sudden [Metamagic] (Complete Arcane) - Instantly apply a metamagic feat.
Transdimensional Spell (Complete Divine) - Metamagic: your spell can hit enemies on other planes of existence.

Versatile Spellcaster (Races of Dragon) - Spend 2 lower-level slots to cast a higher level spell.

Weird
Magic of Incarnum gives what is essentially variable feats. Each feat gives you a point of essentia and an ability that lasts for 24 hours that costs essentia. You get essentia back when you rest. Some of them are pretty cool. You can only spend 2 points of essentia on any one feat (at level 6). There's a feat that lets you spend more, up to your con modifier. Nick may outright outlaw these mechanics, as they're a little wonky. The really basic stuff is kind of cool, though.
Complete Scoundrel offers a bunch of luck reroll feats. They are pretty neat, and allow for some potentially powerful tricks. I'm not sure how powerful they are, but they seem neat at the very least. The luck feat to reroll initiative seems particularly good.
Frostburn gives a lot of cold elemental type spells, and while Sandstorm has similar ones for "desert-ey" games, it only has one "fire subtype" ability (Blazing Berserker). For mages of another elemental type, I'd consider asking for the Frostburn type feats, but in fire, acid, or electric form, depending on what kind of elemental type you choose. You may even want to go further and ask him for other spell types, such as compulsion, charm, or other spell types that aren't elemental, as many of the feats are just "buff save DC of cold spells."

E6 Feats

These are not yet Nick-approved for the most part.

Fighter and BAB
Unless otherwise stated, all of these may be selected as fighter bonus feats.

The Art of War
Requirements: Character level 5, Armor Proficiency (light), Weapon Focus (any martial or exotic weapon)
Benefit: Your base attack bonus increases by +1. This cannot increase your base attack bonus above +6. This feat may only be selected once.

Battle Practice
Requirements: Character level 6, Armor Proficiency (light), Weapon Focus (any martial or exotic weapon), Power Attack
Benefit: You are considered to have four additional levels of fighter (with a maximum of 6) for the purposes of selecting feats. This feat may only be selected once.

Master of War
Requirements: The Art of War OR Monk level 6
Benefit: Your base attack bonus becomes +6.

One True Style
Prerequisites: Fighter level 6
Benefit: You may select feats with a requirement of up to fighter level 8, and with a base attack bonus requirement of up to +8.


Versatile Style
Requirements: Character level 6
Benefit: Your ranger, barbarian, paladin, and monk levels are considered fighter levels for determining what feats you may select.
Note: This feat in particular might allow these classes to be too versatile when compared to pure fighters. It's just an idea, and this feat is one of those I'd definitely consider rejecting.

Barbarian

Enrage
Requirements: Power Attack, Cleave, Armor Proficiency (light), base attack bonus +4
Benefit: You can fly into a rage once per day. In a rage, a you temporarily gains a +4 bonus to Strength, a +4 bonus to Constitution, and a +2 morale bonus on Will saves, but take a -2 penalty to Armor Class. The increase in Constitution increase your hit points by 2 points per level, but these hit points go away at the end of the rage when your Constitution score drops back to normal. (These extra hit points are not lost first the way temporary hit points are.) While raging, a you cannot use any Charisma-, Dexterity-, or Intelligence-based skills (except for Balance, Escape Artist, Intimidate, and Ride), the Concentration skill, or any abilities that require patience or concentration, nor can you cast spells or activate magic items that require a command word, a spell trigger (such as a wand), or spell completion (such as a scroll) to function. He can use any feat he has except Combat Expertise, item creation feats, and metamagic feats. A fit of rage lasts for a number of rounds equal to 3 + your (newly improved) Constitution modifier. You may prematurely end his rage. At the end of the rage, you lose the rage modifiers and restrictions and become fatigued for the duration of the current encounter.
Note: I personally think that precision-based damage (sneak attack damage) should not be allowed during a rage, either.

Swift Steps
Requirements: Character level 6, Run, base attack bonus +6
Benefit: Your land speed is faster than the norm for your race by +10 feet. This benefit applies only when you are wearing no armor or light armor and carrying less than a medium load. Apply this bonus before modifying your speed because of any load carried or armor worn.
Note: Due to the awesome wording of the feat, we have no worries about stacking movespeed for barbs or clerics with the Celerity domain. This still allows monks to stack movespeed, as their movespeed bonus is an enhancement bonus. This is allowed in the actual game rules (by multiclassing barb/monk) so it seems reasonably okay.

Uncanny Dodge
Requirement: Eyes in the Back of your Head (Complete Warrior)
Benefit: You retain your Dexterity bonus to AC (if any) even if you are caught flat-footed or struck by an invisible attacker. However, you still lose your Dexterity bonus to AC if immobilized.
Note: Thank goodness for Complete Warrior giving me a good feat to build from.

Improved Uncanny Dodge
Requirement: Character level 5, Uncanny Dodge
Benefit: You can no longer be flanked. This defense denies a rogue the ability to sneak attack you by flanking, unless the attacker has at least four more rogue levels than than you have character levels.
Note: This needs more prereqs, as it is kind of strong for multiclass rogues.

Bard

Improved Inspire Courage
Requirement: Bard level 6
Benefit: Increases the benefits of your inspire courage to +2.

Cleric

Bonus Domain Spells
Requirement: Cleric level 1
Benefit: Choose a domain available to your deity. You may now prepare spells from that domain in your domain spell slots.

Bonus Domain Power
Requirement: Bonus Domain Spells, character level 6
Benefit: Choose a domain for which you have the Bonus Domain Spells feat. You gain the domain power associated with that domain.
Note: You may want to limit a cleric to 3 or 4 domains, maximum; this is mainly so that CLR6 can get up to the same power level as a PrC cleric (more or less).


Practiced Turning
Requirement: Character level 6, ability to turn or rebuke undead
Benefit: Your cleric level for the purposes of turning undead is treated as four levels higher, with a maximum of your character level. This feat alters your base turning level, and feats or abilities which raise it (or rolling higher on your turning check) still apply normally after this feat.


Restoration
Prerequisites: Character level 6, ability to cast 3rd-level divine spells, Wisdom 18, Healing 9 Ranks
Benefit: You can use Restoration, as the spell (paying the material component), with a casting time of 1 hour.

Magic, UMD, and Item Creation

Arcane Literacy
Requirement: Use Magic Device 9 ranks, Knowledge: Arcana 5 ranks, Knowledge: Local 5 ranks
Benefit: You can read all types of arcane scrolls as though the spells are on your class list. You must still meet all attribute requirements required. If you do not meet the attribute requirements, you may still use UMD to emulate the appropriate attribute.

Divine Literacy
Requirement: Use Magic Device 9 ranks, Knowledge: Religion 5 ranks, Knowledge: Nature 5 ranks
Benefit: You can read all types of divine scrolls as though the spells are on your class list. You must still meet all attribute requirements required. If you do not meet the attribute requirements, you may still use UMD to emulate the appropriate attribute.