I spoke to a friend last night who hadn't heard about this, so I figured I'd spread the word.

On 31 March 2007, 2.2 million people and 2100 Sydney businesses turned off their lights for one hour - Earth Hour. This massive collective effort reduced Sydney's energy consumption by 10.2% for one hour, which is the equivalent effect of taking 48,000 cars off the road for a year.

Now, even if you find these statistics hard to believe, please join, it'll make a difference either way.

At 8pm March 29, 2008 millions of people in some of the world’s major capital cities, including Copenhagen, Toronto, Chicago, Melbourne, Brisbane and Tel Aviv will unite and switch off for Earth Hour.

Even if you live in a small city - JOIN!

Visit EarthHour for more information and for sign ups!