I hate the term "Web 2.0" -- one day I hope it makes the banished word list. But I love what it encompasses, and The ESP Game is one of those loves.

Each time you play you are randomly paired with another player whose identity you don't know. You can't communicate with your partner, and the only thing you have in common with them is that you can both see the same image. The goal is to guess what your partner is typing on each image. Once you both type the same word(s), you get a new image.

Addictive fun and you're tagging Flickr photos. Ah, the great Googlization of the internets (er, or in this case, Yahooization). Rock on.