I've often written (although never on Big Think, until today) about Kiva, a nonprofit organization that connects charitable donors with microfinance institutions that cater to entrepreneurs in the developing world. Kiva's partner organizations make loans - typically just a few hundred dollars, small by American standards, but huge in many developing countries - to people who want to start a business or expand an existing business. By promoting economic growth in developing countries, mostly to people who are usually overlooked by traditional banks or preyed upon by loan sharks, microfinance offers one of the few real ladders out of poverty.
Kiva donors can log on to the site and see the beneficiaries of these loans, which they can backstop with their own money in $25 increments. The best part is that, because the loans are paid back over time, Kiva donors have their money returned to them, allowing them to lend it out again and again in a virtuous cycle. (If this all sounds a bit confusing, see this list of current loan recipients, any of which a Kiva member can fund.)
This is an excellent idea, and what makes it even better is that the largest lending community on Kiva is made up of atheists, who've collectively loaned almost $7 million in over 228,000 individual loans. The Kiva atheist team was the first to break the $1 million milestone, and currently has over 20,000 members, more than twice the Christian team, which is the second largest. I'm one of those lenders, happy to play whatever small part I can.
I bring this all up because, at the moment, Kiva is making a particularly inviting offer: they're giving away 10,000 free trials, each of which comes with a $25 credit that allows a new Kiva lender to make one loan free of charge. If this appeals to you, then follow this link to sign up. (If you join through that link, I'll be listed on your account as the referrer. I won't get any money or anything else of value for this.) The free trials may not last long, so take advantage of this offer while you can!