Today a tidal wave of aging boomers want income, but traditional sources are lacking. But there's [a] source of high yield that relatively few consider. Peer-to-peer lending, or making personal loans via the Internet using websites like LendingClub.com and Prosper.com. After six years of experience and some bumps, including a financial crisis and ensuing recession, peer-to-peer (P2P) lending has finally earned its place on an income investor's menu. The basic premise of these bank disintermediaries is that they harness the networking power of the Web to match people who have excess cash with people in need of it or those who simply want to refinance credit card debt. The key to its success has been how the sites have managed the inherent riskiness of unsecured personal loans. Believe it or not, it is now possible to earn yields of 6% or more, making relatively safe loans to complete strangers. San Francisco's Lending Club is the largest P2P lender, followed by its crosstown rival Prosper. Lending Club and Prosper have loaned a total of more than $1 billion since inception, in 112,000 loans. Lending Club currently issues about $45 million in loans a month versus Prosper's $13 million per month. Of course defaults happen. Lending Club's top-rated three-year loans expect a default rate of around 1.4%, and the riskiest loans, offering rates as high as 25%, have a 9.8% default rate.