Last week the Microsoft Live Labs team released the first version of Photosynth that allows you to make your own synths! Just log in and throw a bunch of images at it and they "automatically reconstruct a three-dimensional space from a collection of photos of a place or an object."
I took a large pool of photos when I was in Thailand earlier this year and built my first synth with it. It turned out fairly well. This is the courtyard of Wat Benchamabophit in Bangkok. Of course, mine is only 76% synthy. This seems to be a measure of how well it is able to stitch the photos together in the 3D space. They also have some tutorials on how best to take photos to make them more synthy.
They have a number of really good examples from National Geographic.