Hi. I've been working on a system very similar to OPs description for months now -- http://portobello-road.org . Must be an idea who's time has come, eh? Now I know how Newton and Liebniz felt when they discovered they'd simultaneously invented calculus. Aside from a few architectural decisions (hubs and marketplaces instead of DHT for seller data dissemination and indexing) things are much the same. Would love to join forces and do something cool. I've already gotten a whitepaper put together (though very incomplete I've done a lot of the work in getting a build system for LaTeX up and going and a structure in place) and an initial implementation of a downloadable nodewebkit client and some server code. Just starting on documentation of the communications protocol and getting things going, so it's not very far along. Open to all discussions and debate regarding architecture and specifics.