The first place I saw effects like this was in OS X 10.4 Tiger, where fast user switching (switching users without logging out logged in users) utilized a rotat

The first place I saw effects like this was in OS X 10.4 Tiger, where fast user switching (switching users without logging out logged in users) utilized a rotating 3D cube transition a lot like the desktop cube (just without gaps on the cube edges and the camera looking straight on instead from an upper angle). I thought it was a bit of a brilliant metaphor for multiple users, with each user’s desktop representing a different “face” of the computer, and switching users is an infrequent enough of a thing that the effect doesn’t become grating. It’s a bummer they removed the effect a few releases ago. Full-on compiz effects with burning windows and all isn’t quite my thing, but I think that modern desktops would benefit a lot from judicious usage of “fancy” animations that go beyond the bog standard fade and scale effects. If designed well they can communicate a lot to users.