Also, on a related topic, be careful about how you wrap up your AC/DC power transformer plugs — you know, the famous “wall warts”. If you pull the cord tight and wrap it around the unit it will eventually (and sooner than later!) break at the point where the cord goes into the box.

Best solution I’ve found: put two fingers at the spot where the cord attaches to the unit and then wrap it around. When you pull your fingers out there will be enough of a loop left to provide strain relief and prevent premature breakage.