For some time now, I've been wondering about a way of handling the first stage of a home invasion. These usually start with one person coming to the front door and asking for some kind of favor; a glass of water, use of the phone or to go to the bathroom. As soon as the homeowner opens the door, the person and her accomplices barge in, slam the door shut and beat up the home owner. You'll notice in all this there's no time to go to the gun safe and get your M9. I think the solution would be some kind of a spring loaded doorstop in the floor. The homeowner, feeling suspicious, would step on a protruding rubber button and a spring loaded rod would pop up about four inches behind the door. The homeowner could then open the door and talk to the person outside. If that person then tried to smash their way in, the homeowner could pick up a strategically-located can of bear spray, spray the assailant, then slam the door shut and lock it. This would give time to get a handgun and phone the police. The reason this is better than a chain on the door is that the chain alerts the assailant who then tries to talk their way past the chain. The invisible doorstop, on the other hand, can be activated by foot as the homeowner opens the door. Since the assailant has never heard of such a thing, he/she then tries to force their way in, initiating the assault. This sounds workable to me. Any comments? Suggestions on where I can get a spring-loaded bar assembly?