If you’re looking for the ultimate in concealablity that fits in your pocket, check out this North American Arms (NAA) Mini Holster Revolver. Chambered for .22 Magnum rounds, this minuscule handgun folds up and clips inside your pocket, with only the pocket clip showing so it just looks like you have a pocket knife. When unfolded, it locks into place and fills your hand so you can shoot it accurately when you need to.
The size isn’t the only thing that’s small either. The price is only $250!