Images: Microsoft's 3D photo album

Based on technology developed at the University of Washington, Microsoft's Photosynth browser can draw from personal photos or shots culled from photo-sharing sites to create a 3D space users can "walk around" in.

Here, for instance, selected pictures of Paris' famed Notre Dame cathedral (left) are assembled into a 3D model around a relatively simple rendering of the facade (right), based on the position the photographer was in when each shot was taken--a puzzle the program solves using various algorithms.

Viewers use the interface (bottom) to move around the space: The program shuttles them to the next shot while providing renderings that create the illusion of a seamless environment.

Photosynth also lets its users find shots that are similar to a given photo--a historical view taken from the same vantage point, for example.