Photosynth presentation | Venture Itch
I think this is a bit of old news, since I wasn't running windows XP in order to view the demo at their website. For the last 10 years or so, I've always thought that computer vision has been still trapped in the realm of research labs. But things are starting to bear fruit. Image registration (lining up images) isn't an easy task, since lighting, shape, perspective all have to be taken into account. It becomes especially from difficult if you have to do it from 3 space, as is done in the demo. However, it seems like everything's preprocessed, so it looks fast.
I don't think it's a far stretch to say that you can also register people's faces, so you can find all the images with your face in it, taken from different perspectives.
I also wouldn't be surprised that all the tagging of people going on in facebook photos is training a classifier to recognize and register people's faces.
The ones that push innovation and create new markets are the ones that open up possibilities, and show others what was previously thought impossible.