Want to see the difference Earth Hour has made?

http://www.boston.com/bigpicture/2009/03/earth_hour_2009.html

Earth Hour began in Sydney in 2007, when 2.2 million homes and businesses switched off their lights for one hour. In 2008 the message had grown into a global sustainability movement, with 50 million people switching off their lights. Global landmarks such as the Golden Gate Bridge in San Francisco, Rome’s Colosseum, the Sydney Opera House and the Coca Cola billboard in Times Square all stood in darkness. Earth Hour is a message of hope and a message of action. More than 1,000 cities in over 80 countries observed Earth Hour 2009 on Saturday March 28th, as homes, office towers and landmarks turned off their lights for an hour starting at 8.30 pm local time to raise awareness about climate change and the threat from rising greenhouse gas emissions.

The Boston Big Picture website has an excellent collection of a series of before-and-after photographs - which will fade between "on" and "off" when clicked.

http://www.boston.com/bigpicture/2009/03/earth_hour_2009.html