Earth Hour: Brands and Consumers Switch Off, Tune In

8:30pm on Saturday, March 26th marks the fifth Earth Hour, an annual switch-off eco-event that was started as a single-city event (Sydney) by the WWF and the Sydney Morning Herald newspaper in 2007.

More than 4,600 cities, towns and municipalities participated last year, seeing landmarks such as Big Ben, the Empire State Building, the Sydney Opera House, the Eiffel Tower, the Parthenon, the Brandenburg Gate, and China's Forbidden City go dark for an hour. Corporate sponsors have included Coca-Cola, Wells Fargo, IKEA, HSBC, PwC, Accenture and Nokia Siemens.

This year, the theme is "Earth Hour Plus," in which participants are being urged to do one other green action i(n addition to turning off the lights and powering down) via new apps this year, including a FB app from Ikea.

Other brands supporting Earth Hour 2011 including YouTube, Caesars Entertainment, Coca-Cola, Hilton Hotels and Walgreen drugstore, which all plan to turn off their lights. Coca-Cola will switch off its electronic billboards in New York's Times Square and London’s Piccadilly Circus, while AT&T will power down its AT&T Plaza Dallas.