How to change your X resolution on the fly with xrandr

This is a nice tip on how to use xrandr in a terminal window to change your X resolution in Unix/Linux:

http://howto.wikia.com/wiki/Howto_change_screen_resolution_while_in_X-Windows

To see avalable options set in /etc/X11/xorg.conf
Execute: xrandr --verbose
output:
SZ: Pixels Physical Refresh
*0 1024 x 768 ( 347mm x 260mm ) *85
1 800 x 600 ( 347mm x 260mm ) 85
Current rotation - normal
Current reflection - none
Rotations possible - normal
Reflections possible - none
Setting size to 0, rotation to normal
Setting reflection on neither axis
To change the display resolution to 800x600
Execute: xrandr -s 800x600
An alternative way to change settings it to use the number presented by xrandr --verbose
Example: xrandr -s 0
For: *0 1024 x 768 ( 347mm x 260mm ) *85
other common display resolutions are
640x480
800x600
1024×768
1280×1024
1600×1200

ubuntu xorg for projector:

https://lists.ubuntu.com/archives/ubuntu-users/2006-August/089561.html

Solaris xorg for projector + multiple monitors:

http://solaris-x86.org/download/xorg/xorg.conf.toshiba.m2.projector.1280x1024

for openbsd, start here:

http://openbsd.org/faq/faq11.html#amd64i386