I never use the Caps Lock button. Never. The only time I "use" it is when I accidently press it and start typing things in UPPERCASE. To disable it in Linux all you have to do is enter this on the command line:
$ xmodmap -e "remove lock = Caps_Lock"
To set this permanently, just stick the above line in your
~/.bashrc file (or
/etc/bash.bashrc if you're root) so that it looks something like this:
if [ "$PS1" ]; then # Disables the bloody CapsLock button xmodmap -e "remove lock = Caps_Lock" ... fi