I've been trying to figure out that one also, and i have found a solution that seems to work well for me.
-open a terminal and go to your home directory ( /home/username)
-type ' rm .gnome-desktop/* ' to get rid of current icons
-then type ' chmod 550 .gnome-desktop ' this will disable anything from writing to your desktop directory, hence when nautilus tries to put the desktop icons back on, it won't be able to write to the directory.
you still have desktop functionallity and no icons making it ugly
enjoy,
Ray Kivisto
www.raykivisto.com