A Carbon Offset Exchange in the Vio sim has been set up in SL. For the cost of 400 Linden, you can offset your SL carbon footprint for a year.

And what exactly is the cost of your carbon footprint? According to the sponsor, 4Offsets.com, a Web site hosted on a server that hosts 150 other sites uses approxmately 0.01133 tons of carbon dioxide per year.

4Offsets.com also offers carbon offset purchase plans for your car ($40/year), truck ($60), and your homepage ($1). The company claims you can offset your page – be it SL, Facebook, MySpace, or Friendster – and it will be interesting to see if carbon offsetting became a trend in social networks.