This is a cool program being initiated by Nobel Prize winner Wangari Maathai from Kenya. She is the only black woman to ever win a Nobel Prize. Her goal is to have 1 billion new trees planted across the world in 12007 in an effort to stall global warming. All you have to do is click here and enter any trees you may plant during the year so that they may be counted.
You can read about it on Yahoo! News or at the United Nations Environment Programme.