GDM should support Fast User Switching on local GDM displays.  These include:

 - GDM logins
 - GDM connections to external computers over XDMCP
 - Generally, anything GDM that you can chvt or C-A-Fx to

This excludes anything on a remote, Xnest, VNC, or non-GDM (i.e. KDM, XDM)
display; although non-GDM displays are a potential consideration.

The idea would be to compliment the "New Login" command in the Applications
menu.  It should be possible, from GDM or from Applications->System
Tools->Switch Users to change between logins using chvt.  Remember that some
displays may be on vc/2047 or so, which can't be switched to by ALT+F2047; chvt
can change to those vts.

Mock-Up

 =======================================================
| Quick User Switch                                    X|
|-------------------------------------------------------|
| You can switch to another login session here, in case |
| multple people are using this computer.               |
|                                                       |
| You can only switch to login sessions started on THIS |
| COMPUTER; login sessions from other computers on your |
| network, i.e. over XDMCP with the GDM chooser, will   |
| only be accessible from the computer originally used  |
| to log in.                                            |
|-------------------------------------------------------|
| New Login                                             |
|  linus                        idle 3 minutes          |
|  spender                      Active                  |
|  patrickv                     idle 5 hours 11 minutes |
|  spender (2)                  idle 7d 19h 13m         |
|  kthompson                    idle 23y 17d 7h 19m     |
|  [Waiting New Login]                                  |
|_______________________________________________________|

This is also a knock-off of XP's Fast User Switching; but logging out sucks
anyway, and there's no pride in avoiding a good idea just because someone you
don't like did it first; of course we'll see religious arguments the day this is
implimented, but this isn't a sociology discussion.

A mimicry of the WinXP login screen would be possible too, though scrollable and
optionally more compact (by default or, optionally, if there's a lot of login
sessions).  Potentially make clicking a username for a logged in session show a
list of all sessions, to chose from.

Switching to a running login session should not ask for the user's password;
instead, switching away should blank the screen and demand a password, so that
switching back (via alt+F8 or chvt!) would not be able to bypass password
authentication in some environments.  The locking program (gnome-lock?) would
need a button available to kick the user back to the login screen!  Many users
won't know to ALT+F7 back!

Potentially, you could make "New Login" fault to existing New Logins, or even
keep ONE GDM login up and always spawn a new X when logging in.

These enhancements would make the machine easier to use for multiple users, such
as families.  It would also just plain be cool.


As a far future thought, by using an intermediary X server that proxies X
commands or such, the same session could be accessed from various terminals
without VNC (like XDMCP where you can disconnect and not log out).  Remember,
VNC takes screenshots rapidly, compresses them, and forwards 'em over network;
while XDMCP sends X packets over network.  One is a lot easier on bandwidth than
the other!