OK, full disclosure: I work for Greenpeace International in Amsterdam. But even if I didn't, I'd put them up there in the ranks of the worthy.

For starters, they were talking about this issue in the late 80s with a "Fossil Fuel Free Future" that was ahead of its time. They did some important work internationally putting the issue out there. In the intervening they:

Created a pressure campaign that got Coke, McDonalds and Unilever to switch their refrigeration methods away from CFCs:

http://tinyurl.com/fguey

Partnered with industry to create "Greenfreeze" CFC-free refrigeration:

http://tinyurl.com/nj5n6

Lobbyed the World Business Council into a pro-Kyoto position against the will of the US members:

http://tinyurl.com/nayqg

Greenpeace may not be the new cool in environmental advocacy (I note they don't even get a link in the sidebar here at WorldChanging), but in a world in which the nuclear industry's advertising budget alone is (way) bigger than their annual budget, they're still boxing above their weight.

Personally, I'd split my donations between Greenpeace (think global) and smaller local groups doing the nuts and bolts work to ensure renewables are on a level playing field with big oil, that consumers get incentives to buy green, and that your own power isn't coming from nuclear or coal.

Here endeth the sermon. ;-)

--b