Our website server, DreamHost, is carbon neutral. They've calculated the impact of everything that they use and leave behind in the course of their daily work. (All of the resources that they use -- paper in the office, electricity for their servers, even the gas in their cars that bring them to the office -- leave behind some kind of "unfriendly" residue in the world.) You can read about all the efforts they are making to reduce waste in their website.

www.dreamhost.com/aboutus-green.html