Somebody in the army had a great idea for using some of their advertising budget. They created a combat simulation video game called America's Army! Apparently it's so good that all West Point cadets are issued a laptop with the game installed. and of course you can play over the net. and it's free since it's an advertisement!
They just created a linux port of the game, and an OS X version is on the way.
The gentoo linux guys have created a new live cd with America's Army on it! The idea is you put the cd in the drive, boot up, and you're in a live gentoo system. then you can run the game without ever touching the hard drive.
And of course there is a bittorrent for it! I fired it up this morning. it downloaded pretty quickly. I plan to leave my bittorrent client open all weekend, gotta help out gentoo any way I can!
once you get your bittorrent client installed, here is the bittorrent link