If you had the right robots to do it, while you sleep they could keep your hair trimmed, your face (or legs) shaved, your fingernails and toenails clipped and all that other body maintenance stuff that currently takes up your waking time. The potential down side is that, if you wake up and see a robot hovering over you with a straight razor, you'll probably not get back to sleep.
Mokalus of Borg
PS - And you'd want to be a heavy sleeper for this.
PPS - Or for the robots to be microscopic and unobtrusive.