Microsoft's Photosynth project which has been around in a limited demonstration form for a while now as a Live Labs project was finally released in a fully functioning version a couple of weeks ago.
For those of you who have not heard of it before is is an application that allows you to upload photos of an area and have them converted into a 3D representation of the area like a school or monument integrating all of the images into a single environment. There is a demo video of the original concept here(TED).
The live site is here: Photosynth
It is still a Windows only application but is impressive none the less and far more useful now that users can add their own images to create their own environments.
The original Live Labs project has been mentioned a few times before in these threads: