Today I showed my pocket knife, which I keep very sharp, to several people and commented that I routinely carry it in my pocket aboard airplanes. Turns out that blades under 4 inches don't count. Maybe the terrorists didn't even have to hide them. What HAS been questioned while going through the X-ray machine is...my pennywhistle. "What's that long thin metal thing in your bag?" When I told them it was a whistle, they never bothered to look. "Take this plane to New York, or I'll PLAY!"