Here are some great websites that I am addicted to right now!

This is a cool website where you can flick a switch. It's really cool, and it supports earth hour!
http://www.earthhour.org/kids/lightswitch/Lightswitch.aspx

This is another website for earth hour... you get to make your own lantern! It's great fun!
http://www.earthhour.org/kids/MakeALantern.aspx