Google has turned out the lights!

http://www.google.co.uk/intl/en_uk/earthhour/

Google users in the United Kingdom will notice today that we "turned the lights out" on the Google.co.uk homepage as a gesture to raise awareness of a worldwide energy conservation effort called Earth Hour. As to why we don't do this permanently - it saves no energy; modern displays use the same amount of power regardless of what they display. However, you can do something to reduce the energy consumption of your home PC by joining the Climate Savers Computing Initiative.

Obviously Google.com will talk about the US, rather than the UK, but it's the same regardless (saying that, the European Googles don't seem to have turned off their lights. But then again, I wouldn't expect that of the Italians... though I would of the Germans).