http://www.marginalrevolution.com/marginalrevolution/2008/12/is-micro-credit.html
In the context of PG's essay "Be Good" (http://www.paulgraham.com/good.html), this makes a lot of sense. Not in terms of fleecing the world's poor, but as a smart investment that happens to be nearly indistiguishable from charity.
At the moment I'm still a little averse to the stock market, but I do have some savings and I'd like to put some portion of it to better use (no major financial commitments on the horizon). These organizations piqued my interest:
Kiva -- http://www.kiva.org/
United Prosperity -- http://unitedprosperity.org/
Silicon Valley Microfinance Network -- http://svmn.net/
Anyone here have some experience with these groups, or other microfinance ventures?