In winders, I use a little utility called IconCorral. I can give it an executable name or a window title, and whenever I minimize the named application, it removes the taskbar entry and moves it to the system tray (next to the clock) with a little icon. It's nice because then I can have lots of apps running in the background, with quick access, without cluttering up my taskbar. Is there anything like that for linux in general or Gnome under FC4 in particular?