Advogato's trust metric is severely underutilized given the amount of collaborative platforms popping up in webland. What gives?
For all the interest, both academic and pragmatic, it's remarkable how little implementation there is (worth noting is UCSC's wikitrust). The problems do not seem intractible and the problem domain itself is quite fascinating, yet so little to show. Are people just using web site selection to do ranking ("bookmark trust") and leaving it at that? I'm surprised there so little desire for a unified field of discussion and knowledge, it could create a new economy of ideas as well as a marketplace for allocating decision-making authority and governance.