The Dewey Donation System has this really cute logo of a little dot with a book on its head . . . oh, you want to hear what it does.
The DDS (way different from the DDC; and if you laughed at that joke, you're a librarian) calls attention to people or libraries in dire need of books. The libraries set up Amazon wish lists, nice people buy books, Amazon sends them and everyone's happy. The DDS has helped out Oakland Public Library after catastrophic budget cuts, San Diego Public Library after wildfires, Indian schoolchildren after the tsunami, and now have turned their formidable attention to Katrina-devastated libraries in the Gulf Coast.
Do it because you're a nice person. Or because you really, really need brownie points in heaven after that crazy weekend in Vegas when against all reason and laws of mathematics, you may have actually broken eleven commandments. Y'know. Either way.