Last night we where at a friends house, he was showing us some of his guns. He is retired army.
He has a (I think) its a army issue colt 1911 (if thats not it, its very similiar and aperrantly made the gun a long time, since 1890's or so), and he showed me the three methods of safety on it. One was in the rear of the grip, another words, it wouldn't fire unless the palm of your hand was squeezing it. and one of the other methods was if the end of the barrel was pushed "in", it wouldn't fire.
He said most don't know about that one, and supposebly was designed that way in case your attacker grabbed your gun and pointed it at you at close range (say...at your chest), you where to push yourself into the barrell, and it wouldn't fire.
Made total sense when he demonstrated it.
very very very cool