I set up Xubuntu 11.10 on the Dell 531S driving the Thing-O-Matic, as the Unity UI seems surprisingly like crippleware: every feature that isn’t mandatory is prohibited. However, Xubuntu’s XFCE UI also has a long list of things that should be easy and aren’t, such as enabling remote desktop sharing. Gotta have that so I can fire up the printer and monitor progress from upstairs.
It turns out that the Vino server is installed, but not enabled, so you must start by firing up vino-preferences in a terminal to set some preferences:
This is a local machine behind a firewall, so a moderately secure password with no confirmation will suffice. Your paranoia may vary.
Then drill down through the menu from Settings → Settings Manager → Session and Startup to the Application Autostart tab, then Add the Vino VNC Server to the list: /usr/lib/vino/vino-server. You can start it manually if you have the hots for immediate sharing.
This seems to be impossible in Unity, trivially easy in GNOME, and unduly mysterious in XFCE.