Hey, carry a .22. I carry a .45 1911 all the time. Then once in a while, when it is super hot, or I can't hide it I carry nothing. And you know what? That is dumb. All the talk of a .22 not being enough is bs. It is better to carry something vs nothing.
I now have a Walther P22 and I love it. Not to mention, the .22 rounds I use are pretty hot. And they will definitely do damage, I'd still love to see someone take 4 or 5 shots of this stuff in about 2 seconds in the face and not go down. The fact is, I can put 6 shots touching each other at 9 feet, while in the same time i can probably just be getting off my second .45 shot. Especially if I just totally deafened myself or blinded myself with muzzle flash. The .22 has no recoil, I can get off the 10 shots in a nice 4 inch group in about 4 or 5 seconds. Plus if you've ever got a good hit on a coyote or something, you know that .22 will do its job if placed right.
If you want to carry a .22, carry a .22. It is better than buying something big and not carrying it at all.