In 2007, 2.2 million homes and businesses in Sydney switched off their lights for an hour, and within a year, the event grew into a global sustainability movement.

Last year, 50 million people switched off their lights. 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.

This year, WWF has an even more ambitious target. To help them reach it, join Skype and vote earth. The result of the vote will be presented to the United Nations Climate Change Conference in Copenhagen later this year, and WWF are hoping to get 1 billion votes for Earth.

We’ll be turning off all of our office lights for the hour, and Skype employees across the globe will be joining in – and we hope that you do the same.

It’s our opportunity to demonstrate to world leaders that we care about tackling climate change – calling on them to take action to save the planet for future generations.

So don’t forget Earth Hour: 8:30pm local time, wherever you live on planet earth. Saturday 28 March 2009.