While researching my last post, the Google side bar linked me to Treeflights.com, a British company that plants trees for each flight you take. The amount of carbon release getting a plane to lift off is huge. "We plant one tree for each flight so that your trip gets greener - and a small forest on a Welsh mountainside gets a little bigger." At only £10 (about US$20) per one-way flight, Treeflights.com is a great way to help make your flights carbon neutral.