Sorry, couldn’t resist on this one. Apple has announced “Spaces”, a virtual desktop capability in its new release of Leapord coming later this year. Finally! This was just about my favorite UI feature of the Sun Solaris OS back when I worked at Sun starting in 1992. While Expose is a cool effect I rarely use it for actual work. But virtual desktops (which allow you to have different apps set to run in different desktops which you can seamlessly switch between) are a real productivity gain. Instead of having all your running applications and files piled on top of one another, you can separate them into conceptually different, er, spaces. This is especially useful for what Alan Cooper calls “sovereign” applications, those which justifiably take up the entire screen.
Apple’s implementation is characteristically elegant and well-thought out judging by the video, and takes advantage of graphics and processing capabilities not possible 13 years ago. Better late than never, though, eh?