i finally took the plunge. all emacs gurus advocate that the caps lock key should be remapped to be a control key. i have been defferring that for some time now but today i finally took the plunge when i had to hit C-u M-. several times in conjunction with source code browsing using etags. its hard to rewire the brain and its tough to fight the muscle memory. anyways
setxkbmap -option ctrl:swapcaps http://www.emacswiki.org/emacs/MovingTheCtrlKey
update :: 18april2010
on arch linux i wanted to do the same so i put the following in my .bashrc
setxkbmap -option ctrl:nocaps
this just makes the caps lock key in to another control key rather than swapping it.