Pushing the Desktop Metaphor
Despite the metaphor, current virtual desktops (a) have little resemblance to the look or feel of real world desktops (b). Bumptop explores making virtual desktops behave in a more physically realistic manner (c) by adding physics simulation. Objects can be casually dragged and tossed around.
Bumptop.com (thanks to Jack van Wijk, for the tip)