I have read a few articles on using a GA for animation - ie letting the animation evolve itself. Is there a program to do this, or do I have to write one myself?

Umm, I would think that if you want to use it in your own applications, you would have to write one yourself, unless there is a library out there that allows you to do this easily, which I kind of doubt.

That would probably take longer than making the animation manually.

http://www.naturalmotion.com/

That costs a lot :-(

Any equivalent for 2d?