Recent 360 and Live buyers get two free XBLA games
>> From joystiq.com:

QuoteMicrosoft offers two free Xbox Live Arcade games if you bought a 360 and Live account over the past year. Fill out a short registration form and enter code "XBX0807" to qualify. However, the site is cagey about which games youll get. The terms and conditions state that youll receive an email code by September 30 to download the titles, but the offer "will be for games selected by Microsoft."

Link?

http://xbox360.joystiq.com/2007/08/17/recent-360-and-live-buyers-get-two-free-xbla-games/