This from Wired Autotpoia:
Folks who don't want to trade in their ride for an alt-fuel vehicle or hybrid can buy some peace of mind.
"Green tags" as discussed in BusinessWeek are stickers that you can put in your car to mollify your guilt about polluting. The tags are used to buy clean energy to offset the fumes that your car is producing.
While I appreciate the support for cleaner air, changing behaviors (walking, taking a bus, or upgrading to a better mpg vehicle) is a much more powerful statement. It feels like buying an indulgence as an easy way out.
(Photo Courtesey of Zenrid's flickr Photostream)