Ford Lane-Keeping Bed
Bed hogs, get back in your lane! Ford's one-off bed prototype uses the same principles as their vehicles' Lane-Keeping Aids do in monitoring road markings and "nudging" drivers back in their own space, but here keeps encroaching sleepers on their rightful sides of the mattress.
The Ford Lane-Keeping Bed uses pressure sensors to detect when a sleeper has crossed into his or her partner's territory, and then uses - get this, straight off the auto manufacturing line - an integrated conveyor belt to roll them back onto their own side.
Presumably the "block 'n' roll" is gentle, and able to activate without waking either party up, but even if it does disturb the space stealer, I'm still in favor of the Lane-Keeping Bed. Maybe after enough nudges the space-stealer will learn not to cross the center line. A little Classical Conditioning in action.
Apparently, along with the Lane-Keeping Bed, Ford has released a series of prototypes called Ford Interventions as a way of showing how automotive expertise can apply to everyday problems. Honda did something similar a couple months ago with their Sound Sitter, a car engine noise baby soother.