Xfire is a free utility that automatically keeps track of when and where gamers are playing PC games online and lets their friends join them easily.
Xfire works regardless of game type, server browser, or gaming service that a player is using. Xfire eliminates the hassles of running multiple programs like IRC, instant messengers, or in-game friends lists to keep track of when and where a gamers friends
are playing.
Xfire supports the best and the latest online PC games including server- and non-server-based First Person Shooters, Real Time Strategy, and Role Playing Games.

key features:
Xfire keeps track of when and where your friends are playing PC games online and lets you join them easily
Xfire provides a powerful server browser
Xfire allows you to IM with your friends from within games while you play
Xfire provides a powerful file download system
Xfire provides built-in stats tracking
Xfire provides miniprofiles
See when your friends are online, what game theyre playing, and what server theyre on
Join in on their games with one click
See what the friends of your friends are playing