If you missed out taking part in Earth Hour 2008 this weekend, there’s always next year. In fact, on the earthhour.org website, there’s already a place for you to sign up for the 2009 event, which will fall on March 29.

So, what was it all about? Simply this, for the second year in a row, millions of people all around the globe flipped the switch, and sat in the dark for one whole hour. The reason? To play a role in making a difference and raising awareness about global warming.

Even internet search engine Google jumped on the bandwagon, changing its usual white background to black for the day, with the message, “We’ve turned the lights out. Now it’s your turn.”

“This is the perfect opportunity for individuals, governments, businesses and communities around the world to unite for a common purpose, in response to a global issue that affect us all,” said the World Wildlife Fund’s Carter S. Roberts.

Crowds turned out in cities that chose to be a part of it all to watch their local “lights out” ceremonies. Atlanta, Phoenix, San Francisco, Chicago, Toronto, Canberra, Sydney, Brisbane, Manila, Dublin, Copenhagen and Bangkok were some of the larger participating cities.

The Earth Hour website urges everyone to make it more than a one hour observance by always turning off appliances not in use, switching to energy efficient light bulbs, or turning out lights when you’re not in a room.