Free game from Valve until 24 May 2010 :-).
http://store.steampowered.com/freeportal/

We used 80 KWh less electricity at home than last quarter. That's 711 Wh less per day than last quarter. 17% less power for the same money!

If you build web apps, this might be useful: http://googleonlinesecurity.blogspot.com/2010/05/do-know-evil-web-application.html