I saw this on hackaday today. It's a pretty neat little circuit for powering a machine on and automatically powering it off if left idle for too long. I guess the power down delay is adjustable.
Not a really exciting item, but I can see how it might be handy. It's pinball related so it has to be good.
Of course it could work just as well on a vid or probably lots of other things... like maybe the clothes iron or coffee pot or the like.
http://hackaday.com/2012/03/01/auto-power-circuit-for-an-arcade-machine/Girl in picture is not me. I'm not a girl and my face breaks cameras so...