Switch monitors from the command line

With the commands

xrandr --output VGA-0 --auto
xrandr --output LVDS --off 

The screen automatically transfers to the external display. It doesn't even need sudo powers. To find out the name of the displays just do:

xrandr -q

Which should give something like:

VGA-0 connected 1280x1024+0+0 (normal left inverted right x axis y axis) 338mm x 270mm
...
LVDS connected (normal left inverted right x axis y axis)
...

Extending the displays can probably be achieved in a similar manner.

This is most certainly NOT a direct answer to your question. But I found it helpful in my use case. This is not an export of the config file, but it does show how to automate disper in a shell script. I'm setting this up to run every time I dock/un-dock and it seems to be fixing my display issues when docking and undocking my laptop:

You have to have disper and Python installed.

#!/bin/sh
#
# Detect displays and move panels to the primary display
#

PYTHON=python2.6
DISPER=/usr/bin/disper

# disper command will detect and configure monitors
$PYTHON $DISPER --displays=auto -e -t left

# parse output from disper tool how many displays we have attached
# disper prints 2 lines per displer
lines=`$PYTHON $DISPER -l|wc -l`

display_count=$((lines / 2))

echo $display_count

echo "Detected display count:" $display_count

# Make sure that we move panels to the correct display based
# on the display count
if [ $display_count = 1 ] ; then
    echo "Moving panels to the internal LCD display"
    gconftool-2 \
    --set "/apps/panel/toplevels/bottom_panel_screen0/monitor" \
    --type integer "0"
    gconftool-2 \
    --set "/apps/panel/toplevels/top_panel_screen0/monitor" \
    --type integer "0"
    sleep 5
    pkill gnome-panel
else
    echo "Moving panels to the external display"
    gconftool-2 \
    --set "/apps/panel/toplevels/top_panel_screen0/monitor" \
    --type integer "1"
    gconftool-2 \
    --set "/apps/panel/toplevels/bottom_panel_screen0/monitor" \
    --type integer "1"
    sleep 5
    pkill gnome-panel
fi