One thing that has always annoyed me is there is no nice way of
resizing your X desktop without editing config files. And no, Ctrl
Alt +/- on the numeric keypad only adjusts the virtual resolution,
not the actual desktop size! I've heard of extensions such as the
new XRandR (X Rotate and Resize) but this does not work with all
the different X servers out there, and not always with 3D support either.
So I've developed a little program called xchanger. You prepare
an XF86Config-4 file and place in #ifdef statements to switch in
and out various features. I have written a little shell script using
dialog to allow you to specify resolutions for your laptop LCD and
external display, select dual head or cloned mode, and specify the
type of external display. So you bring up the tool, configure the
new options, and then hit Ctrl-Alt-Backspace to restart the X server
and you are in the new resolution. This is really useful when you
are giving presentations on your laptop and need to quickly jump
between resolutions to make it work on the projector.
Xchanger is available via the GNU GPL and a tar ball can be downloaded
here. It works on both Linux and FreeBSD, and with both XFree86 and XOrg. You can also install the easy Debian/Ubuntu package by following
my above APT instructions and then apt-get'ing the tinmith-xchanger
package which will fully install it for you. I've prepared
templates that are designed to work on Nvidia and Radeon cards
that I have, and should be pretty generic for you to use without
having to play around with anything!