A while back I experimented a little with an online gizmo called The Hero Machine. It was fun, but ultimately unproductive. Bryan at Spare Change alerted me to the new and improved Hero Machine 2.0. This one is much better—more fun and way more productive. My wife and I both used it to create images of what we would look like as superheroes.
Just so you know, they're both spot-on accurate, except that I don't usually wear a cowboy hat (though I would if I were a superhero) and I don't have a dog (but I would if I were a superhero).