While you won't find me hugging any trees things to help minimize our impact on the environment is always a good idea. I have to say that my kids will definitely have the lights out during this hour because they are usually asleep. Not sure if I can convince them to give up the night light, but it is at least an LED light. I did find a website that has more Earth Hour info and other activities for kids and teens. It's earthhourkids.org.
And here is Earth Hour 2009 video: