Speaking of knives and security:

I have always carried a pocketknife since I was a little kid. I used to think of it as essential equipment, like a handkerchief. Right now, I have one with a 1¼-inch blade on my key chain. In the past, I have carried bigger ones, for example Swiss Army knives with a 3-inch blade. Most of the time, I forget I have it, and it never occurs to me that it might be a security problem.

I even carried it (inadvertently) into Stillwater State Prison! I was a techie with a theatre group that went there to perform a play. We brought boxes and boxes of equipment, which the guards didn't bother to inspect. They didn't even tell us what we couldn't bring in. They happened to see one actor carrying a thermos full of coffee, and they said, "You can't take THAT in" - only because it happened to be out in the open instead of in a box or a pocket.

At one point, while setting up the equipment, I needed to cut a piece of twine that I was going to tie something up with, so I whipped out my case knife and cut it. There was a prisoner standing near me, and I'll swear I saw his eyes bug out. That's when it dawned on me that I probably shouldn't have brought it in. But he tried to act nonchalant and so did I. I put it back in my pocket and neither of us said anything.

When we were leaving, some of the prisoners wanted to give us something to show their appreciation. So they gave us some of their official "tin cups" (stainless steel, actually) that they drink coffee out of. We smuggled them out in our boxes of equipment. I still have mine.

Sorry for the thread creep, but if security in a prison is that lax, why would you expect anything tighter in an airport?