Comment 2 for bug 156705

A workaround of sorts for this limitation, using packages from the Ubuntu repository, is to launch a separate Gnome session within a nested Xserver like Xephyr. Xephyr can be installed using apt-get.

You can then share just this desktop, by pointing and clicking within the GUI of the the conventional remote desktop sharing wizard, but inside the nested Gnome session you've launched.

I wanted to permit my GF to also control the LastFM program on my desktop. The script I use to launch the gnome session looks like...

#!/bin/bash
startx /usr/bin/gnome-session -- /usr/bin/Xephyr :1 -screen 800x600 &

I then launch LastFM inside this window where she can get at it with the password configured through the 'Remote Desktop' gui (the Gnome Menu name for the package vino) inside the newly launched Gnome session.

The configuration made through vino seems to be long-lived between sessions, so only has to be done once for each display port you ever launch. The next time the launch script is run, it's automatically password accessible.

If you wanted to make things more secure, you could try launching a Xephyr window on behalf of a different user account. I haven't tried this, and don't know how this plays with Dbus, Pulseaudio and the like when there are effectively two users logged in to the same multimedia hardware device.