Earth Hour 2010, on Saturday March 27th at 8:30pm (local time), is a global call to action to every individual, every business and every community throughout the world. It is a call to stand up, to take responsibility, to get involved and lead the way towards a sustainable future.

Iconic buildings and landmarks from Europe to Asia to the Americas will stand in darkness. People across the world from all walks of life will turn off their lights and join together in celebration and contemplation of the one thing we all have in common – our planet.

Earth Hour started in 2007 in Sydney, Australia when 2.2 million homes and businesses turned their lights off for one hour to make their stand against climate change. Only a year later and Earth Hour became a global sustainability movement with more than 50 million people across 35 countries participating. Global landmarks such as the, Sydney Harbour Bridge, The CN Tower in Toronto, The Golden Gate Bridge in San Francisco, and Rome’s Colosseum, all stood in darkness, as symbols of hope for a cause that grows more urgent by the hour.

2010's event is expected to draw the most support ever. In the U.S. alone, 30 states will participate with landmarks like the Empire State Building, the Golden Gate Bridge, the Las Vegas Strip, the Niagara Falls and the Willis Tower, set to observe the event.

"This year's Earth Hour promises to be even bigger than last year. Already, 92 countries have signed up for Earth Hour 2010 – up from 88 countries in 2009 when an estimated one billion people across 4,000 cities flicked off their lights," said WWF-Australia's national project manager for Earth Hour, Jennifer Croes.

So do whatever you can and turn out the lights to your dorm room, or your entire house – but take an hour to enjoy light of another kind starting at 8:30PM!!

Click here for more info or to join an event near you.

Click here for a slide show of Earth Hour around the world in 2009.

Watch videos from previous Earth Hours below and send your own in to Live Earth video!