Unithrive is a non-profits that allows alumni to help students by granting interest-free loans. Currently only alumni and students of Harvard can sign up, but Unithrive plans to expand to other schools in fall 2009.
Students can borrow between 500 and 2,000 US$ per semester. Repayment begins after they graduate.
The founders Joshua Kushner, Nimay Metha and Tanuj Parikh recently graduated from Harvard. For more on Unithrive read this recent New York Times article.
Duck9.com is positioning itself as a peer to peer lending service for college students. Lenders can invest a maximum of $10000. In the video below Duck9 founder Larry Chiang explains the business model and the benefits for lenders and borrowers.
The video is from October 2006. It might be a bit outdated. While Chiang says in the video that lenders receive a free $100 to lend, the site currently states: "NOTE: there is a SIGNIFICANT waitlist to be a lender. Money isn't accepted while you're on the waitlist".