"A team from the University of Washington (UW) has developed a new computer algorithm that uses hundreds of thousands of tourist photos to automatically reconstruct an entire city in about a day. It's thought that one use for the technology could be to provide visitors with an on-line virtual-reality 3-D tour of cities they visit.
UW has been studying ways of utilizing the increasingly large digital photo collections available on photo-sharing websites like Flickr. The digital Rome was built from 150,000 tourist photos tagged on that site with the word ‘Rome' or ‘Roma' (there are around 2 million ‘Rome/Roma' images on the site)."
Within just 21 hours, the algorithm was able to compile the images to create a 3-D photoreal model of the city. The researchers say they'll be able to model any city with large amounts of photos and essentially create virtual tours.