I've been thinking about a way to mitigate lending risk through an expanding web of m-of-n transactions and historical analysis. I think it will work, but will still require collateral. Why not offer collateral to be used by someone that needs it? If you have a time-share, a sports car, or maybe a boat, it can be lent out to someone that is part of a collateralized lending web of trust. This is similar to other ideas out there, but the main difference is that removes some of the trust. Open Transactions might be a good way to implement this.