A South American folktale from Wangari Maathai, the Nobel Prize-winning founder of Kenya's Greenbelt Movement:
There is a terrible forest fire. All the animals are fleeing the conflagration except Hummingbird, who is flying back and forth, scooping up little up little slivers of water from a spring and dumping them on the flames. "What do you think you're doing, stupid little bird?" the other animals ask derisively, and Hummingbird says, "I'm doing what I can."
As we enter the season of giving, it's good to remember that sometimes all it takes to make a difference is to try.
UPDATE: Thanks for Francesca for this link to a short video clip of Maathai telling the hummingbird story.