This little picture doesn't look like much, but it performs well. At the linked site, take the dark striped section at the right and move it slowly over the picture section. Here's
a post that explains how this type of animation is made.
Link -Thanks, Jon Jason!(image credit: Rufus Butler Seder)
It doesn't look too insanely difficult to make either... would be a neat project for me to take on ^_^
It's full of loads of animals with this animation thing, it's sweet as and you can get em at firebox if ya want em.