What do those keys do on a Mac? What I like in my KDE/Linux combination (though I think windows may have that also, I haven't used it in a while) is that I can decide to have any number of desktops and I can see all of them in the control panel, and can just click on any of the miniaturized window outlines on that mini desktop representation if i want to go say from my browser window to my graphics program or editor on a different desktop without having to press the key that lists all my windows or something even more complicated.