Xfire is a IM system from gamers. It tells what game you are playing, and how many hours you have played it overall and weekly! Also, your friends just have to click a button to join you if you are playing an online game!
You can also record, take pictures, make guild, and do many other things on this program! If you are a PC gamer this should not be overlooked.
One negative though, sometimes xfire slows down your PC when you're on a game, so keep that in mind!