If you don’t have access to a Windows installation, this post is not for you (yet, Microsoft claims to be working on a Mac version), sorry!
Photosynth is really cool. It’s a tool from Microsoft to visualize spatial environments using overlapping photos. It really is something else—way better than a static slideshow, it manages to give you an idea of space and volume by stitching together an environment from different views.
It makes me want to go out and take some photos of Oxford. If I have a chance tomorrow, maybe I’ll shoot a couple dozen views of Oriel’s quad, and then see how easy it is to put together a visualization. In the meantime, enjoy the Taj Mahal as seen by National Geographic photographers.