A useful rundown of some of the considerations worth keeping in mind when evaluating the "green" credentials of a web host or service.

Michelle also links out to the Green Web Hosting Directory, which I've seen pop up a bit recently. It seems my own host, Krystal, isn't well represented there, which is a shame given all they're doing to reduce their environmental impact. I've reached out to the company to see if they can maybe increase their verification level.