This made us laugh. The Off light switch hook, designed by Die Electric, promotes keeping lights turned off, we guess. But seriously, maybe the switch could be reversed so that when a coat hangs on it, pushing it down, the light turns on.
That way, when you're home the lights can be on. And when you take you coat from the hook and go out, it's a constant reminder to turn the light off (or even spring load it so the light's turned off when the weight of the coat is removed).
Anyway, there are lots of other similar great designs by Die Electric, which is an electrical outlet product collection by product designer Scott Amron. The Off switch hook pictured up top sells for $35. (via Treehugger).