Groupon is offering a twofer. Buy one Kiva card (to give away or use yourself) and get a freebie Kiva Card which will act as a promotional loan. Repayments on the freebies go back to Kiva, while repayments on the purchased cards go back to the lender as usual. You can buy up to four Kiva cards (and get up to four freebies) using the deal. Hurry, as it only lasts a few more days. http://www.groupon.com/deals/kiva
In addition to leveraging the promotional credit (which Kiva usually gets to recycle), note that one can link through mileage malls when purchasing from GroupOn. Can think of it as GroupOn's way of thanking you for supporting others through Kiva.
Went through the AA mall for 3x miles, and spent $75 to get the bonus 1K miles. Then my wife did the same (by proxy, with my fingers doing the typing and my brain making decisions) for $100. She'll hopefully get 1300 AA miles for that. You can use all the codes to make loans from a single Kiva account. Happy Monday.
And for those who have already maxed out the holiday mileage promos for airlines, MyPoints is offering 16 points/$ at the moment for those with accounts. With the more valuable redemption options, this is effectively a 10%+ rebate (and can also be redeemed for UA miles).