Came across a chart that might be useful for writers who are putting mouseguns (small-caliber pocket pistols or revolvers) into their stories. It give you a pretty good size comparison of various pistols, and also a snubbie revolver and full-sized slab-side semi-auto to show how the semi-autos stack up against the J-frame.
If you are looking for concealed carry for summer, where a holster under a jacket won't work, or a big honkin' belly pouch will give you away, small handguns are an option. Yes, yes, a .357 Magnum or a hot-loaded .40 S&W or .45 Colt ACP is a better gun to have if the shit hits the fan, but the old saw holds true: A mousegun in your pocket is better than a real gun at home in the drawer. Much of the clothing worn on a hot summer day make concealing a legally-carried piece difficult. If you are wearing a "fisherman's" or "photographer's vest," or are sporting a belly or fanny pack big enough to haul around a phone book, everybody who knows squat about guns will know you are strapped, certainly every cop will.
I can remember being asked once by a local LEO if I was a retired cop. I raised an eyebrow and he nodded at the belly pouch I was wearing. Only thing he didn't know was what the piece in it was; he was sure I had one.
There are times when you absolutely don't want anybody to know you have a gun concealed on your person. A small enough gun can be worn in an IWB holster with a T-shirt concealing it, or carried in a pocket or in a small leather belt pouch. If you are wearing your wife-beater shirt and in a pair of cut-off jeans at ninety degrees, that full-sized piece is hard to hide if you can't store it in n-space, like Batman's utility belt ...