Beavers are cute, wonderful to see, and even nicer to pet. If you have a nice tame one at home, that is. And it also turns out that their dams can slow down oil spills and keep them out of sensitive environments, as happened recently. What's good for beavers is good for humans everywhere, I always say. Some of the valiant oil-besmirched beavers were even cleaned up and nursed back to health.