taketwo,
Not that it matters, but why not under?? It would be all of about one inch from where the switch is now (put it at the bottom, just behind the edge of the faceplate), and just as easy to flip on/off (unless someone had really, really fat fingers), and would give you a cleaner look esp. since it's not some really great looking switch.
There's already a main power switch on the back, which is typical and harder to get at, but doesn't need to be 'gotten' very often. Having two in the back might force a lot of people to have to 'look' at the back, where-as only one switch on back lets you reach back there 'blind'.