I like to think of myself as a pretty good this Flash Actionscript. I can write code for pretty much any idea my little brain can come up with. Then you see the work that Jared Tarbell is going on Levitated.net and you realize just how much I still have to learn.
Levitated.net houses some of the best and most intriguing Flash open source I have found. You can get code that will do everything from generate simple color patterns all the way up to a collection of small, one legged swimming automatons that combine when they collide. My favorite is called Walking Things which generates small, walking computational organisms. Each walking thing is built up from totally random conditions like appearance, behavior, and walking style. These characteristics are all assigned from a range enabling effective, functional mobility. Clicking on a walking thing will permutate its characteristics.