This Saturday, millions of people in 3,100 cities from 121 countries, all across the seven continents will switch off their lights for one hour, starting from 8.30-9.30pm local time, in honor of Earth Hour 2010.

The movement which started in 2007, with 2.2 million households and 2,100 businesses in Sydney, Australia, gained popularity after it was revealed that this small 'sacrifice' resulted in cutting back 10% of the electricity consumed by the city in a normal hour - the equivalent of saving the amount of carbon dioxide emitted by 48,000 cars in an hour.

The idea resonated with so many people across the globe, that in 2008, over 50 million people celebrated Earth Hour, by switching off their lights. Famous city landmarks like San Francisco's Golden Gate Bridge and France's Eiffel Tower also went dark for an hour.

In 2009, the numbers went even higher, with over 1 billion people in 4,100 cities in 87 countries, spread across all seven continents, joining the movement.

Will this year be even bigger? If we all do our part, it sure can be. So spread the word and include as many family and friends and neighbors as you can, by organizing a candlelight potluck or inviting them for a fun-filled hour of board games.

Even if you plan on being alone, just switch off all the lights (and television!) between 8.30 to 9.30 pm local time, this Saturday, and do your part in saving our planet, one light bulb at a time! To see how many people are participating or to register your participation, go to www.myearthhour.org.

sources: myearthhour.org