We have made this our home page in the office at CAR Gardens. The idea is that a bright monitor screen uses more energy per pixel than darker ones. Seems to make sense.
It may be that the amount of energy saved is slight, but if we all dropped the usual white Google page it would amount to a lot more saved; wouldn’t it?
And each time we need to do a search in black we will be reminded of the importance of little steps.
If you like the idea, why not spread the Blackle word.