A company called 3PAR is promoting a new idea in computer hardware. When you buy one of their products, they automatically include carbon offsets  for the energy it will use. The products themselves aren’t exactly everyday consumer items, but I can see this idea catching on as manufacturers realize that green values can be a differentiator.
[thanks for the link, Adam!]
 Wikipedia has more info on carbon offsets. They’re controversial, but I personally think they do real good and raise awareness. If people start thinking about the amount of energy something uses as an added up-front cost, it helps make efficiency part of the buying decision.