Coming out of Microsoft Research, the tech preview of Photosynth is now available to the public. Photosynth puts together photos taken from different angles (and most likely by different people at different time) into a 3D viewing environment.
The experience is different than viewing 360 degree panoramas. Because each photo is faded in and out, and the random nature of the time and angles makes it more like putting a puzzle together than being virtually at the location.
To view the demo, a plug-in (~5.5MB) is required.