A way of stripping character levels out of d20.
Problems with levels:
It's insanely difficult to raise your stats just by adventuring; you have to accrue "inherent bonuses", and D&D3 limits you to +5 (rather arbitrary, IMO). Seems to me that adventurers would, over time, just get naturally stronger, smarter, faster, etc.
The feat system is hopeless if there's no way to pick up extra feats, beyond what your class is assigned (if any), which is ludicrous. Also no way to pick up extra skill points.
So, start using experience points to trade in for the usual level benefits directly -- skill points, feats, more hit dice, attack bonuses, that sort of thing. And then determing starting character power by points.
All I'd have to do, theoretically, is come up with point costs for the various level benefits, maybe with class modifiers. And it shouldn't be that hard to do, I don't think. Mostly just quantitative analysis of what various classes get; reverse engineering, so to speak. Cost of various points would be a function of their current levels.
Would also make sense to make initial attribute assignment points-based, while I'm at it.