When your screen is white, either as an empty word page, or a Google page, your
computer consumes 74 watts, and when its black it consumes only 59 watts.
So a man named Mark Ontkush wrote an article about the energy saving that would
be achieved if Google had a black screen.
Taking in account the huge number of page views, according to his calculations,
750 mega watts/hour per year would be saved.
In response to this article Google created a black version of its search
engine, called Blackle, with the exact same functions as the white version,
but with a lower energy consumption, check it out.
This post was edited by Gorgeous George at 20 Aug 2007