It would be so useful, and not very difficult, because in fact I have Directory Opus installed (a very powerful windows explorer alternative) and it does exactly that, but only by double-clicking the desktop, not the taskbar. Similar options with middle-click would also be nice, such as scrolling the taskbar (maybe cycling directly through the Alt-Tab window). 7 Task Tweaker is close to this, actually, but it doesn't do what I would like.