I have to agree with Bountyhunter here, the .22 semi-auto in one of its many guises can be just a fantastic all-around weapon. And as a matter of fact, at close range, you can take a deer with a .22, those Velocitors from CCI are pretty darm amazing - I shot an old 4x4 post yesterday just to see how the exit looked (I know, a deer is not a 4x4) and it was a fist-sized chunk of wood out the back from a .22 at 30 yards. That's a hard hit, and if you have a few rounds of that hard hitting stuff, well, that's a darn fine thing to have.
Anyway...back to urban CCW. Well, yeah, things can get hairy, and in the urban environment, you have all the extremes of society packed in close to one another, so even if it's a "one in a thousand" type of crazy person you're facing, in a city like New York, that's well over a thousand crazies! But again, stealing generators is one thing, and that's not TEOTWAWKI, that's just ordinary criminals acting as they always do. And as the korean green grocers learned in the Watts & Rodeney King riots in CA, concelement of the weapon was quite the opposite of what they needed to - partoling the roof of their store with shotguns plainly visible was far more effective.
Anyway, this thread might do better over on
www.frugalsquirrels.com which is far more amenible to urban survival scenarios during widespread civil unrest.