The ancient city of Rome wasn't built in a day, but now that city, along with all its famous landmarks, can be digitized in just a matter of hours. Computer scientist Steven Seitz and his team at the University of Washington Graphics and Imaging Lab are developing a new computer program that combs through hundreds of thousands of tourist photos on Flickr and other photo sharing sites and reconstructs the city -- pixel by pixel. Now, viewers can fly around (or even through!) many of Rome's famous landmarks on their computer in far more detail than they'd ever be able to on current virtual map programs such as Google Earth. This new technique, developed with support from that National Science Foundation, may one day lead to online maps that offer viewers a virtual-reality experience. The software could also build cities for video games automatically, instead of doing so by hand. And you might one day be able to learn the history of a place just by taking a picture of it with your smart phone!