I've just released code under the GPL for an idea for a universal reputation system that I'm calling the TrustNet.https://github.com/btalabs/trustnet
The basic idea is an append only database of claims, made by ethereum identities about other ethereum identities or about any object. So the idea basically extends Zimmerman's web of trust concept, swapping PGP keys for ethereum keys, and extending the idea of key signing to making a claim of any kind. The claims are stored in the blockchain and cannot be altered.
I've written a bit more about it here;http://bittradelabs.com/blog/lego-for-grownupshttp://bittradelabs.com/blog/finding-analogies
I'm looking for feedback and potential collaborators,