There are a couple of ways to get sneak attack damage on specific types of critters in Complete Adventurer...
There are two feats, Razing Strike and SomethingElse Strike. One allows arcane casters to give up an arcane spell to temporarily allow sneak attacks on constructs. The other allows divine spellcasters to give up a divine spell to temporarily allow sneak attacks on undead. There is also a spell version of each of those feats, also in Complete Adventurer.
Other than that, not really, that I know of.
Later
silver