I have always had a particular fondness for zeotropes since my foundation course at college. Its amazing how easily you can get some animation going with a simple biscuit tin! I experimented using 3D objects on mine (as opposed to drawings). Those that went to the Pixar exhibition at Science Museum in London a few years ago, you will recall the totally amazing 3D zoetrope (you can see a movie of it here). I also stumbled across this link of a life size one! Looks like the people are strapped into a fairground ride of sorts and away they go! You can view it here.