I guess I've just never had sufficient screen real estate for multiple active windows to really appeal to me, except for monitoring purposes.
I give the window I'm working in full screen, and may have many others open in the background. I switch to what I want to do - after all, I have only one input channel, so there's really only one window I'm interacting with at a time.
I use a second desktop because that concept groups the windows that are accessible with alt-tab. When I do my banking, I have Quicken (via wine) and a browser pointed to my bank open, and alt-tab toggles between just those two when I'm on the banking desktop. I can hop back to the general desktop and alt-tab between email, browsing, and IRC.
Amarok is usually minimized, a simple click in the system tray brings me full screen control.
Maybe if I upgrade to a 20" widescreen this summer, I'll see the light.