We've mentioned TED Talks before, and a new video from TED 2007 has surfaced, showing Blaise Aguera y Arcas giving a demo of Sea Dragon and Photosynth technology recently acquired by Microsoft. The truly amazing part starts around 4:15, when a model of Notre Dame Cathedral is shown, using photos from Flickr, automatically mapped together to fit the structure of the building. Definitely worth a look for fans of photography and digital imaging:

You can also try the online demo of Photosynth, though it's Windows-only at the moment.