Jonathan made a great instructable on how to reorder your keyboard keys on a MacBook if you prefer a Dvorak layout (an alternative to the standard QWERTY layout, the Dvorak keyboard requires less finger motion as you type). He also points out that it’s helpful if you just want to give your keyboard a good cleaning. He’ll show you the proper delicate technique for removing and replacing your keyboard keys without damaging them; the MacBook keyboard is quite unique. – Link.