This is a very simple concept but I'm amazed that I haven't seen it yet. Why can't we have smart cards for audio and visual home equipment? Why not a smart card activated hi-fi? It won't turn on without the card and won't turn off unless you remove the card... Or what about the removeable fascia that was used for a car stereo? why not have a fascia that operates both your home and car stereo? I prefer the smart card idea though. If you lose it all you have to do is bring your receipt to...