Happy Earth Day! Is anyone doing anything fun to celebrate Earth Day this year?

I did a few crafts with DD using recycled paper. We made our own paper, and she also made a bowl out of scraps from our recycle bin. http://www.kiwicrate.com/projects/Pretty-Paper-Trinket-Bowl/2009

I love this holiday/celebration so I'm trying to think of other fun things to do to teach the kids about caring for the Earth.