I always seem to forget how to do this…

  1. Alt-F2 or type in terminal: gconf-editor

  2. Apps > Nautilus > Desktop and on the right-side look for ‘volumes visible’

Toggling this will toggle, in real-time, the icons from being displayed on your Desktop

Show mounted volumes on the desktop If this is set to true, icons linking to mounted volumes will be put on the desktop.