Ich benutze ja uControl, um meine überflüssige Return-Taste umzumappen. Ein anderes Programm, was das ebenfalls erledigen kann ist DoubleCommand:

DoubleCommand is a Mac OS X kernel extension that lets you remap certain keys to certain other keys. It started out as a quick way to turn the Enter key into a Command key, but is now far more powerful than ever before. Why would you want to do this? Well, on my PowerBook G3 there is an Enter key to the right of the space bar - where I would really rather have a Command (Apple) key. So now I can! Many people have emailed and requested different key changes, so now DoubleCommand allows you to choose from several key mappings. For the full feature listing look at the install page.