flyboy:
I built a "smart" night light with an ATtiny85 and a motion sensor hacked from an air freshener. It is normally PWM LED at a dim level. If it "sees" you, it goes full bright. After 30 seconds of not "seeing" anyone, it goes to a dim level again.
That's a cool idea too. I need to get a bunch of bread boards so I can make these little projects and set them aside for later rather than pulling them apart each time.