Starting two X sessions with different xorg.conf's?

[Charlie Zender]

Hi X-perts,

I want switch easily between two different X sessions on my laptop.
Session 1 is for my docking station and will use xorg.conf.twinview
which runs X on two external monitors.
Session 2 is for travel and will use xorg.conf.travel which runs X
on the laptop's flat panel display and nothing else.
(Unfortunately, I am not X-pert enough to put both xorg.conf's into
one file and hotswitch between them. Moreover, NVidia twinview does
not make it easy to use the laptop screen while using the two external
monitors...).

Ideally, I will work at my desk using the twinview monitors that are
the default and appear in the session known at Ctl-Alt-F7.
Then, when I need to travel, I switch to the laptop screen session
using Ctl-Alt-F8. After traveling (actually just teaching using my
laptop in another building twice a day), I re-dock my laptop and
switch back to the Ctl-Alt-F7 twinview session.

How should I start these sessions on Kubuntu Jaunty?

The Kubuntu menu allows me to "change user" but it does not allow
me to specify which xorg.conf for the new session. Is there an
alternative like a command line way of starting Session 2 and
specifiying which xorg.conf to use?

Charlie
-- 
Charlie Zender, Department of Earth System Science
University of California, Irvine (949) 891-2429 :)