Tools exist to make stop-motion animation fairly easy ... at least some of the technical aspects of the sport.
We've mentioned iStopMotion for OS X. I used it for a small project shortly after getting an iSight camera for my Mac. I tried a few tests with the current version yesterday and can report it is greatly improved.
A friend spends about half his time at a remote company location. The place has become very boring to him and he decided to make stop motion videos using his PowerBook, iSight and iStopMotion. He has a plywood board that is used as a stage, mounted lights and a camera mount that slides around the board. Some of his work is remarkable ... not at the level of Aardman Studios, but much better than Gumby.
A great tool for being creative and learning the ropes of something that few do. If you become skilled there are higher end versions to support dSLRs.