If a million monkeys typing can write Hamlet, can a million tourists' snapshots map out a 3D picture of Rome?
The answer is yes. And Venice, too.
There are more than 2 million photos on Flickr tagged with Rome. They capture almost every nook and cranny, every column and doorway, of the old city. If you had a lot of computer power, and the right smart software, you could take these 2 million views and compile them into a single unified 3D portrait.
And if this system from the University of Washington GRAIL lab worked for Rome you could take other highly photographed places, such as St Marks Plaza in Venice, and construct a visual 3D picture, down to the smallest detail.
Microsoft's Photosynth accomplished a similar feat. The movie below does that same thing with huge piles of photos taken off of Flickr.
Eventually, the every city in the world will get a full textured 3D view of itself. (via Waxy)