Innovation is the new success mantra. Google, Apple were born with it and Microsoft, now, seems to be desperately developing this 'good' habit. Photosynth is another genuine proof of this (Bing is one!). Photosynth was fabricated at Microsoft's Live Labs (yeah, its Microsoft's take on Google Labs) with the simple mission of reconstructing the 3D world from flat photographs. First came the still camera, then we had video cameras and now we have Photosynth.
So whats being cooked ? Well, Photosynth automatically stitches together normal 2-D images of an object taken from different angles and points and generates a 3-Dimensional re-creation, called a 'synth', of the object. You can somehow compare it to the panorama mode photos supported by modern digicams, but they don't even stand close.
For example, say you have taken pics of Eiffel Tower from different locations/vantage points. Now, what Photosynth will do is, it will automatically examine and compare your pics for similarities, with those images of Eiffel Tower shot by other Photosynth users from similar or different vantage points. It then analyzes the information it has obtained to estimate the size, shape of the concerned object, which in this case is the Eiffel Tower, and re-creates a 3-D view of it (essentially made up of hundreds of images). Now you can roam around the Eiffel Tower and view it from a zillion angles (courtesy those hundreds of images). You gotta see it to believe it. Its pure brilliance.
Read more about it here.