My coworker recently introduced me to this sweet little site sponsored by Burger King promoting the new Simpsons movie. All you need to do is upload a face shot of yourself and KAZAAM! It will simpsonize you! After the site creates your initial character, you can customize it to look more like you. Lydia and I did one for each of us and then we pasted us all together. I had to use a little bit of Photoshop mojo to make Santa's Little Helper look like Zeus, but I think he turned out pretty good!
Give it a shot! I'm excited to see what other people look like.