Usually a concealed weapon makes more sense than a visible one, but from time to time I have a big, shiny, stainless 1911 sticking out of my belt with the hammer back and frankly I'm not ashamed. Here are a few facts (not opinions, but facts) about myself:
I am not confrontational.
I don't stare anyone down, even if they start it.
I don't draw undue attention to myself.
I don't break a single law if I can avoid it.
I don't handle my weapon, adjust my weapon, or otherwise contact it.
I don't expect special attention, respect, or obedience.
I don't cut in line, start fights, or coerce anyone around me.
If you panic at the sight of me (well dressed, well spoken, and polite in manner) simply because there is a weapon in my waistband, I feel a bit of pity for your lack of education but no compassion for your emotion. I'm not sorry if you're offended, and I won't apologize. I am more than happy to discuss the reason for and legality of my status as an armed citizen - in fact, I'd like to help you understand. I am not interested in compromising.
I've never seen an openly armed, un-uniformed individual behave in any other way, to be honest. We're peaceful people in general. You can take that statement to the bank - the statistics for legal gun owners' violent crime rates speak for themselves. I would venture to say that most open carrying folk have a concealed permit as well, which generally covers your request for assurance of the individual's reasonable competence. The OP and several folks chiming in seem to be genuinely afraid of the gun itself as they're giving no benefit of the doubt to the people who choose to wear one.
Oh, and one more thing. I've never had anyone start a fight with me, mug me, stalk me, or even get loud while there is a visible weapon in my possession. It's kind of a nice side effect - an armed society is a polite society, I believe they say.
Why exactly is it that you would have me disarm, or even hide my armament? Perhaps you are frustrated that you can't expect me to roll over if you want to be combative? Are you jealous of my comfort with a potentially dangerous tool? Do you superimpose a bunch of egotistic nonsense upon me simply because you cannot understand my mentality, or choose not to try? Are you afraid that because I possess the power to end a life, that I will use it without discretion? This is the problem with the wrongly educated anti-gun crowd: You know what you want, but you can't really tell me why.
And for the next topic: To those who believe that the constitution can be bent to the will of the government because some of the things it guarantees are outdated or unnecessary, go pound sand. The point is to enforce respect for ALL of its limitations to the government so that they can NEVER EVER violate the rules at their whim. The fact that you disagree with the right to bear arms is fine and you're allowed to be offended by my pistol, but if you allow your leaders to step on the second amendment, I can think of nine more that will follow quickly.