what about that alternative ipod firmware bubba linked too a while back
actually, if you can install rockbox that will remove the volume limit as it's a software (not hardware) implementation.
Apple: 1st through 5.5th generation iPod, iPod Mini and 1st generation iPod Nano(not the Shuffle, 2nd/3rd gen Nano, Classic or Touch)
The volume on my creative zen is really crap too, is there anyway to solve that?