Have a look on a new Search Engine called "http://blackle.com" with a  black background.
The idea behind this is to save energy every time we search something on the net.

Blackle has been customized by Search Giant Google which means that each search on Blackle uses Google search prowess.

The argument is simple: An all white background uses more energy to display than a black background.

Now, if Google, which gets 200 million queries a day, turns its background black, some amount of energy will be saved.