Google now has a "Green" options in their mapping service. I would be interested to know if they are getting paid to list places as "green" or if they are doing it just as a service.

trex005.googlepages.com/maps.g ...

trex005.googlepages.com/green. ...

It looks like a promotion of their Summer of Green campaign, which is partnered with "Earth Day Network":
blogoscoped.com/archive/2006-0 ...