GoAnimate

As someone who's into comics and animation (mostly Japanese), I played with strip generator in the past, which is kind of fun. Macbooks also comes with a nifty program for creating your own comic strips, complete with different layouts, conversation bubbles, etc.

I read about GoAnimate today, enabling users to create animations without drawing. They just announced the introduction of Star Trek animation. Pretty neat stuff. Can't wait to find some time to try it out!