The easy if lo-tech way is to take the key off the keyboard.
There's probably software that will let you do this too, but it's under some other guise. Quickkeys or something maybe? There might be some others out there thatallow you to remap keys and such. Try versiontracker or macupdate for ideas, and maybe someone else would know. And now that I think of it, you might do a search of www.macosxhints.com
which has plenty of geek-speak hacks for OS X in one place.