More than 400 buildings in Atlanta's skyline will turn off the lights from 8:30 to 9:30 p.m., including the World of Coca-Cola, Peachtree Center and even the Varsity drive-in sign. It's not to confuse you. The event, called WORLD WILDLIFE FUND'S EARTH HOUR, represents participants' demand for world leaders to take action on climate change. Organizations and households worldwide pledge to turn off all nonessential lights for one hour in support of climate change initiatives. Joining in are other major U.S. cities, including New York, San Francisco and Las Vegas. Free. www.earthhourus.org.