One of the advantages of using Unix-based operating systems was the opportunity to try any number of different solutions for managing windows in a GUI. (This led to a disadvantage of incredibly inconsistent user experiences between and sometimes even within applications, but what the hell.) One idea I’ve had for a while, which used to be impractical but is no longer so clearly problematic, is to have a real 3D interface for window management.
Apple’s Expose demonstrates that it’s technically possible: though the windows have been reduced to arbitrary percentages of their original size, they continue to update and behave normally.
What I’d like is to be able to move windows forward or back, and for their size to change with their distance. Maybe a control key and the scroll wheel when on a window’s title bar, and the window moves forward or back on the stack. As it does so, it becomes larger or smaller.
Each window would have its own notional pixel dimensions that assume a minimal distance, but the windows could be resized arbitrarily without changing that notional pixel count. One could keep many windows open but shrunken around the edges of the screen, then find a particular window visually, center it, and move it to the front.
I would find this both intuitive and practical: I could select windows visually, watch progress of operations, and still not suffer from a lack of screen real estate. (Even my 20″ cinema display is just not enough. If I had a larger desk, I might consider a larger display already…)