We’ve written about a number of microfinance organizations in recent years, including not just oft-cited Kiva but also Wokai and Jolkona. Whereas those ventures all strive to help entrepreneurs in the developing world by facilitating direct microloans and donations, however, California-based nonprofit United Prosperity is taking a different approach by focusing on providing loan guarantees instead. A traditional microloan or donation of USD 100 delivers roughly that same amount to the entrepreneur in need, but providing a loan guarantee of the same amount can result in a much larger loan from a local bank, United Prosperity says—as much as USD 666, in this case. How it works: Potential guarantors browse the United Prosperity site, which features a number of prescreened entrepreneurs in developing countries. They then choose one to help, and contribute a loan guarantee of any amount through PayPal. United Prosperity then consolidates the guarantees on multiple loans for the microfinance partner involved and issues a guarantee, which is deposited as collateral with the local bank. With the assurance of that collateral, the bank is then willing to lend funds—the amount depending on the guarantee percentage it requires—to the microfinance institution, which in turn lends to the individual entrepreneur who was supported. The guarantor can track the entrepreneur’s progress building their business, and when the entrepreneur repays the loan, the funds are returned to the guarantor’s PayPal account. United Prosperity, meanwhile, earns interest on guarantee funds; it’s also considering charging its partners a small fee for providing the guarantee. Now in beta, United Prosperity cites many advantages to providing loan guarantees rather than simple p2p loans: the process allows recipients to develop a credit history, making future loans easier to obtain; it reduces the interest rates banks charge the microfinance institutions involved; and it better manages risk while providing a more scalable model. So far, 111 guarantors have used the site to help 105 entrepreneurs with more than USD 11,000 in guarantees. One to partner with, emulate, or otherwise get involved in…?