http://www.darkoogle.com/

Why black background ? According to a quick study earlier this year showing that if Google was black then 750 Megawatt-hours could be saved per year and this is because more powers are used to display a white screen than black screen.

Why Green text? Many people has already found that green text are much more visible and easier for our eye (I guess thats why most computer/terminal was black and green in the old days until the mac came out). So the green text is used with the black background to reduce eye strain while at the same time saving energy when searching google.

So spread the word and start using Darkoogle http://www.darkoogle.com/ to save energy!