The online magazine Slate has an interesting article on peer-to-peer microfinance organizations. Via their websites you can select the entrepreneur to whom your money will go yourself; like ebay for microloans. Read the full what's the best way to loan a poor entrepreneur $20? article.
Slate's winner: "Kiva combines online community with microlending in a way that's truly exciting. It's remarkably compelling to see your borrower face to face..." Got interested? Invest via Kiva.