UX Outside the Box
So, when someone suggested that adding a motion sensor to a flashlight may be a nifty idea, it could easily have been just another redundant gimmick.
Maglite has gone ahead and done just that, and they've pulled it off, in my opinion:
That right there is a magnificent display of a human-machine-interface, because it's simple, and it works in a way that doesn't require much thought at all. The flashlight itself becomes a rotary switch. Genius.
It also serves as a reminder that user experience (and usability in general) - and inspiration to make things easy - isn't limited to what we see on screen.