Community

If you own a nvidia graphics card, (i'm not sure it actually checks) then you are entitled to some free games on Steam.

Games:
Portal: First Slice (11-level demo)
Half-life 2: Deathmatch
Half-life 2: Lost Coast
Peggle Extreme (I had to search and manually download this one.)

http://www.steampowered.com/nvidia/#

Update: it does check your graphics card, Nvidia users only.