From JanUNC
Computer scientists from the University of North Carolina at Chapel Hill and the Swiss university, ETH-Zurich, have invented a technique that creates 3-D models of landmarks using pictures readily available on the Internet. Millions of images can be processed on a single personal computer in less than a day.
source PhysOrg
On another note, you can now visit ancient Rome in 3D on Google Earth:
From SBARTSTV
This is the first 3D ancient city to be featured in Google Earth.