I feel so overwhelmed and helpless by the oil spill in the Gulf, I've gone into complete emotional fatigue on the subject. Ever since the first photos of oil-covered sea-birds had me bawling into my keyboard at work I've avoided thinking about the subject as much as possible.
If you haven't seen it yet (I'm always late to the party these days with my restricted internet time), here's a Pet Connection post with a depressing title but good links.
Also, Charity Navigator has some suggestions.
Personally, I like the looks of The Alabama Wildlife Fund.