Best Friends is the absolutely top drawer animal society! Anything they do is fantabulous.
They have great working vacations where you can help out at the Society in Utah --- doing work with whichever animals you find most compelling.
We set up a provision for our wedding wherein people could chosee to give to Best Friends or the Society for the Preservation of New Hampshire Forests. It was a second wedding for both my hubby and me; we're both in our 40s; we just didn't need more STUFF. People reacted so positively; I thought we'd get donations out of a few of our guests, but actually the vast majority of them contributed at some level. It was the best feeling in the world (next to marrying a fab snipped critter-loving CF guy, that is).