http://photobattle.me/ basically, pits photos against each other and you vote which is "better". There's a "leaderboard" and you get to see how many wins/losses your photos have. You're allowed to upload up to nine. Could be good if only to inflate your ego every once in a while. It's getting pretty popular, over 60,000 votes in the first 4 days or so.. Chek it out if you're bored?