Found this nifty little thing via Penny Arcade. It's a site where you draw a 2D character and they make it dance around in 3D using Flash. I threw together this stick figure one to see how it works. Sorta neat, and free. But, damn, the music is annoying.
Note that I don't think they thought about scalability on the thing and it's become reasonably popular, so it seems to be hit or miss on whether the thing actually plays.