We mentioned the LinkedGeoData.org project during summer 2009, and LinkedGeoData has just been released as open source on Google Code (via OGD).
The project's synopsis: "In order to employ the Web as a medium for data and information integration, comprehensive datasets and vocabularies are required as they enable the disambiguation and alignment of other data and information. Many real-life information integration and aggregation tasks are impossible without comprehensive background knowledge related to spatial features of the ways, structures and landscapes surrounding us.
LinkedGeoData uses the comprehensive OpenStreetMap spatial data collection to create a large spatial knowledge base. It currently consists of information about approx. 350 million nodes and 30 million ways and the resulting RDF data comprises approximately 2 billion triples. The data is available according to the Linked Data principles and interlinked with DBpedia."