As an avid, if somewhat 'John-come-lately' Mac user, I am still big enough to admit when Microsoft are getting something right. First, I was introduced to local.live.com which appeared to be MS's take on Google Earth. Except I could see my house (in Brighton) from a height of 30 yards, whereas on my version of Google Earth, I am a mere blotch at anything over 6000 feet. AND you can view in a kinda Isometricish planar view. AND from up to four direction. Pretty slick, but original? Probably not. labs.live.comon the other hand is something quite different. Its sort of Flickr, sort of browser, sort of Google Images, sort of thing. And despite the rather cutsie MS style that insists on championing the Ethos of Live Labs, the Photosynth project looks and more importantly, FEELS like something genuinely original and full of development potential.
I'd like to think about this a little deeper, so I'll stop posting for now, but I expect I'll pick-up again tomorrow.