some time ago stardock IRC'ers were throwing around ideas for the future of desktop GUI. My thought was that future GUI's would be 3-dimensional, items layered in the way that they can be pushed forward and back and swung around.
Imagine if all of your apps, start menu, utilities like calculators, and files were all existing at once in a 3d cube that you could move forward and back through? hotkeys would zoom you to each section or you could manually pan around. What if your Word program, with 6 documents open, spun around like a cube as you moved between documents? - all existing at once but only the one side visible at a time. or, you could take the whole cube and alt-drag it to make a clone of it?
we're beginning to get some of these things in a primitive form thanks to widgets and objectdock but its very shallow.
I havn't had the chance to try this yet, but it looks like a step forward in that direction of being unbound by our flat, shallow desktops.
