Blackle comes to us from Google, via a post on Treehugger earlier this year called 'Black Google Would Save 750 Megawatt-hours a Year.'

There is some disagreement as to whether this is fully accurate but Google decided to offer the option. Blackle saves energy, the theory goes, because of its black background. Simply put, it takes more energy to power a light screen as opposed to a dark screen.

And so Blackle was born. Google says, "We believe that there is value in the concept because even if the energy savings are small, they all add up. Secondly we feel that seeing Blackle every time we load our web browser reminds us that we need to keep taking small steps to save energy."

And we say amen to that.