Ubuntu/X11/Xorg caps lock unlock/cancel with shift key

To get your Xorg desktop to behave like a typewriter regarding the caps lock key simply place this line

Option "XkbOptions" "caps:shiftlock"

into your /etc/X11/xorg.conf file and restart your Xorg server, e.g. with CTRL-ALT-BACKSPACE.

Here is where to place the line in the file mentioned above:

Section "InputDevice"
Identifier "Keyboard0"
Driver "kbd"
Option "XkbOptions" "caps:shiftlock"
EndSection

If you use Ubuntu you've additionally to go to

System->Preferences->Keyboard->Layout->Layout-Settings

and change "CapsLock key behavior" to "Capslocks toogles Shift so all key are affected".