Some time ago i saw on TV about this prototype system where you would take a picture of the horizon, and just by analyzing the outline where the sky meets the ground (and buildings etc) , and without the need for a GPS unit nor a compass, it guesses your aproximate location and bearing (provided that the surroundings are in the database); one of the application of the system they demonstrated was tourism, it would identify important landmarks etc and overlay information on the photo about the landmarks, the history of the region, nearby points of interests etc.

Any idea what happened to that project, or if there are any similar services avaiable out there?