Jervous: Try taking off any (sp) abilities, if they have any. That would be a start.
In my game, I wanted a low magic game, with characters using skills and martial abilities to solve problems instead of spells. So, I did the following:
Psionics don't exist (not familiar enough with them)
When preparing a spell (or preparing a spell slot, which spontaneous casters must do), you must take 1 hour per level of the spell. At the end, the DM makes a hidden DC 10*spell level check, where any D20 roll equal to or less than the level of the spell is an automatic failure. The skill for the check is Knowledge Nature for nature casters (Druids, Rangers, etc), Knowledge Religeon for divine casters (Clerics, Paladins, etc), and Spellcraft for arcane casters (Wizards, Bards, etc). When you try to cast the spell, if you've succeeded on the check it goes off normally. If you fail, the spell fails and you take a backlash effect, randomly chosen depending on the school of the spell you tried to cast (so failed necromancy spells do things like cause permanent wisdom decreases and negative energy damage, failed conjurations summon powerful things that attack you or teleport you into physical objects, etc). The save DC against backlash effects, if there's a save at all, is 5*spell level. Every time you cast a spell there's a chance of dying. As such, spellcasters are HEAVILY nerfed, and not expected to be played. When creating magic items, the spells required must be cast every day... so bad idea!
No humanoids or monsterous humanoids (which includes all PCs) can use Spell Like abilities, except for those granted by the Binder and Warlock classes (since those classes draw their power from outside sources).
The game is Gestalt.
All players get the benefits of Vow of Poverty, plus the bonus feats from that are any bonus feat you want (not just exalted), without the drawbacks (you can still use gear). However, there are no useful magic items in the game, so it's all mundane gear. As such, gear is far less important in my game... any random sword works as well as any other, so you can lose all your stuff, punch out a guard, steal his sword, and rock out.
All players heal rapidly when out of sight and no one's after them (fast healing equal to your HD, only when I as the DM decide you're between encounters).
Classes that had casting can, with DM permission, swap out their casting for any one other class substitution ability... for example, the Bard can swap casting for an Animal Companion because of the UA Fey Varient Bard.
Basically, it's a low magic heroic fantasy game. And remember, I like Tier 3 as a balance point. So what do these house rules do to balance?
Well, Tier 1 and 2 are completely gone. All of them depend on spellcasting which is now nerfed, so most of those classes drop to Tier 5-6 (except the Druid, who's Tier 3... yeah, Wild Shape is that powerful). The top tier classes are now the normal Tier 3 guys plus the Druid, except that the Beguiler drops to around Tier 5/6 and the Dread Necromancer does too. Sadly, the Healer and Warmage are also nerfed, but they didn't fit in the campaign world anyway.
The gear changes mean certain specialized equipment dependent builds don't work (Warblade Crossbow archers, for example), and Wild Shape based classes get pumped up (Druids and Wild Shape Rangers) but otherwise changes are minimal as far as balance is concerned.
Healing classes are basically unnecessary, though still handy, so Crusaders are useful to have.
Warlock and Binder invisibility powers are awesome against other humanoids.