The Big Picture has another great photo essay on Earth Hour 2010, with some of the big cities that decided to turn off their lights for one hour on Saturday.  Some of the images are amazing, as you can actually see the stars start to show up (like on the acropolis).

Light Pollution has taken the stars and the milky way away from a majority of Americans, as well as becoming a health hazard.  Hopefully this creates some more awareness on the issue.