today the light on google.de is off:

http://www.google.de/lichtaus/

Also see: http://google.com/lightsoutsf/

[moved from "Google.de turns it OFF" -Philipp]

Google.de turns its background into black to save energy.
8 december 2007.

http://www.google-kai.com/www-google-de-saving-energy-turns-it-off.html