Valve really does seem to be going off in their own direction when it comes to getting games to gamers. Instead of $50 or $60 dollar games, they are selling AAA $20 games (Team Fortress 2), and instead of offering late, crippled demos, they have been indulging gamers with free-play weekends.
In part celebration of the recent to updates to the Scout, Team Fortress 2 will be free to play, come Thursday (until Monday). You just need to get Steam installed and then go here for a pre-load.
If you never played Team Fortress before, or are into team-based FPS games, you should give it a check out for sure.