I like Troy's icon, but it can be confused with screensaver icon (especially the smaller versions) . I think a magic wand on a monitor may work better. See this Tangerine version:
http://xoomer.alice.it/bat/tmp/desktop-magic.png -- "desktop-effects" human variant would be nice https://launchpad.net/bugs/80946 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs