Description of problem:
Provide an intuitive way for people in home computing situations to
switch to a new desktop user without having to logout of the other
user's session.

I think gdmflexiserver as it functions in fedora core 2 is good enough
to be useful as the command to run from a "switch user" menu item.

The only problem I see is the lag in starting up a new gdm login
screen, but functionality using gdmflexiserver seems to act as I would
expect when logging in a new user, switching to existing running
desktops and logging out of a desktop and switching back to an
existing desktop. All without invoking the alt-ctl-# salute to bounce
back and forth. The gdmflexiserver chooser dialog keeps me from having
to use the keyboard shortcut magic.
 
There is probably a corner case when there are N > 2 open desktops and
you logout of a desktop, how do you know which user desktop to go back
to if there are 2 or more remaining.  Other than hacking up
xscreensaver to be able to support moving over to another display I've
no suggestions. But I don't think this is a very large concern. The
alt-ctl-# salute still exists to get out of these situations. 

So I say, put gdmflexiserver into use in a menu item and see how badly
its recieved as a "switch user" utility.