"CabSpotting traces San Francisco's taxi cabs as they travel throughout the Bay Area. The patterns traced by each cab create a living and always-changing map of city life. This map hints at economic, social, and cultural trends that are otherwise invisible."
posted on Apr 6, 2006 - View this thread

OpenStreetMap is a free editable map of the whole world, using uploaded GPS traces. So far: London and several other cities have been mapped. (via dataisnature)
posted on Nov 30, 2005 - View this thread