Anyone had a look at this yet? GDesklets for GNOME -- lets you set up gadgets on your desktop similar to DesktopFX, HoverDesk etc. under Windows.
It's really easy to set up, am already getting good use out of the StarterBar: screenshot
(Excuse the craptacularness of most of this shot, my Gtk theme engine and Sawfish themes aren't quite finished/started yet, respectively.)