I’m doing an exercise animating a hopping ball; being such an animation newbie, I figured it’d be good practice.  You can see what I have so far at:

http://vimeo.com/2151930

The first 2 hops are actually from another exercise, and are a little more refined then the rest of it. I’m still figuring out how to work out beforehand the movement of things (a hopping ball is a little difficult since I can’t just do it myself or easily find reference).

I’m going to spend some time on previs (of some sort or another) then probably start from scratch.  It’s easy to think of a cute little sequence of a hopping ball interacting with a cylinder, but actually animating a sequence in your head (I quickly discovered) is a really stupid thing to do.