a simple, motion-sensitive sleep alarm. i just tried to find one, but they all require a phone or tablet. they're nothing simple and stand-alone with a very basic interface.
so i guess to correct my original post - something more like a simple, traditional alarm clock. with less obvious tech. but that somehow works this same way. basically just a clock display and some buttons to set the alarm time, and i guess some kind of wearable sensor.
[1] http://www.amazon.com/Zeo-ZEOBP01-Personal-Sleep-Manager/dp/...