Kiva is a microlending site where you can give small ($25) loans to entrepreneurs in developing countries. When the loans are paid back, you can reloan the same funds out again to someone else.
Until tomorrow, PayPal is matching $25 loans with a $25 credit to your Kiva account, allowing you to make two loans for the price of one.
http://lend.kiva.org/paypal/smallloansbigim