From the Earth Hour website:
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.
In 2009, Earth Hour is being taken to the next level, with the goal of 1 billion people switching off their lights as part of a global vote. Unlike any election in history, it is not about what country you’re from, but instead, what planet you’re from. VOTE EARTH is a global call to action for every individual, every business, and every community. A call to stand up and take control over the future of our planet. Over 74 countries and territories have pledged their support to VOTE EARTH during Earth Hour 2009....
It's already underway around the world, in some countries Earth Hour is already past. Here in the Heart of the Rockies we're just over 4 hours away. Catch the latest updates, photos, and news here. And find yourself a smile here: