YouTube promotes Earth Hour - YouTube has added a switch right beneath the YouTube logo that allows you turn off the "lights" on YouTube. It makes the background turn dark, and turns off the light bulb next to the logo.

Earth Hour is an annual event where communities and individuals across the globe turn off their lights for one hour. This year, it is on March 26th (the day that I am writing this) from 8:30 to 9:30 pm. To read more on Earth hour, go here: http://www.earthhour.org/About.aspx