Gimundo.com (delivering good news daily) reported that an all-black Google home page saves 750 megawatt-hours of electricity a year. An all-white web page requires about 74 watts to display, whereas a black page requires only 59 watts.
750 megawatt-hours can power for an entire year:
77 North American homes
150 European homes
268 African homes
536 Asian or South American homes
3,750 homes in Afghanistan
6,000 televisions
800 microwaves

An Australian company called Heap Media have created a Google-powered site called blackle.com. The site keeps a running total of the number of watts saved to date. At press time, that number was nearly 135 million watt-hours.

I’ve made Blackle my home page.

Find out more about Blackle.