Portal (PC/Mac) - $0.00 on Steam

[totalnoob]

deal lasts until 9/20.

Go get it, and don't forget to mention this on other forums to spread the joy

http://store.steampowered.com/app/400/

 

[JujuFish]

http://forums.anandtech.com/showthread.php?t=2192022
If it's a deal on Steam, chances are KaOTiK has made a thread.