The ESP Game
You are paired with an anonymous teammate and images flash on the screen one at a time. Type in words that describe the image until both of you type in the same word, then move onto the next. It's fun in a psych experiment sort of way. Aside from playing a game, you're helping label all the images on the Web. And that's important to somebody.
I made a kegz03/kegz03 login. Go ahead and use it.