PlaceDB
This project came out of work at Platial and Thingster. Our goal at the time was to build something that extended beyond the silo model - to be a true aggregator and a true broker of social and place data from all over the web.
The FireEagle team at Yahoo has more clearly executed on this vision and it is a good durable community resource that I recommend you look at as a solution for the domain of problems we were trying to solve.