Kiva (www.kiva.org). Kiva makes microloans to people in developing countries to help them improve their lives/businesses. To steal the United Way's motto, it's a hand-up, not a handout.
People (like me) lend $25 to an entrepreneur until that person's loan amount is met. A local bank (a partner) distributes the money and receives the repayments. That bank charges interest to cover the administrative expenses, but if it weren't for Kiva, the bank would either charge an exorbitant amount of interest, or not lend to that person at all (the most common problem)–either because they are considered too big a risk or the bank won't bother with a loan that's so small (most are $1,000-$2,000 in American dollars).
Kiva does not charge any fees or interest, and people who donate money do not charge anything either. Once the loan is repaid, that money is sent back up to Kiva and Kiva redistributes the money back to the original lenders.
Not only does someone who really needs a loan to improve their situation get the money they need, I get my $25 investment in them back in 6-12 months, which I can then give to someone else. I've had the same pool of money in Kiva for three or four years now, and it just keeps helping people.
For people who might not have much money to give to charity, Kiva makes a small amount of money go on–conceivably–for years. And you select the people you want to help, get to see their picture, rejoice when their business does well and they pay back their loan. It's very personal and very rewarding.