Say what you like about Microsoft - and love 'em or hate 'em, people invariably do speak their mind - they've got some talented people working for them. Their research departments are packed to the gills with boffins developing the wave-after-next of interfaces, GUIs and more, and occasionally we get to see the results. Here, then, is something that could represent a new way of interacting with your PC - or anything else, really, which requires user manipulation. Rather than relying on a mouse or trackpad, a bog-standard USB webcam takes an overhead view of the work surface and tracks the movement of your hand, with clicking and selecting actions operated by pinching the fingers together. The Podtech video explains it better:
If you're interested you can read programmer Andy Wilson's report on the technology here. Will we see this in a future version of Vista? Probably not in any recognisable form, but I've no doubt that with the current hacker's fascination with making the Nintendo Wiimote control just about anything, should Microsoft Research release the code there'd be quite a few innovative applications dreamt up.