Photosynth, Microsoft's software that creates a 3D scene from a bunch of photographs taken at the same location is finally out! I remember looking at the initial videos a couple of years back, where the team was demonstrating the features by displaying a 3D synth of Piazza San Marco in Venice.
The software package that allows you to create your own synths of places you've visited is available at the link below. There is also a short tutorial on how to prepare the pictures for a useful synth, like not photographing one-color areas, or shiny materials, etc. This could be exciting. The only drawback is that the initial version of Photosynth is implemented as a service so you have to upload all the photos to the site. If you have a high-speed Internet connection and are willing to try, enjoy it.