Interesting. The only time that I have ever had a blade measured was at the Holocaust Museum in DC and that was prior to 9/11/01. I would not even try to carry a blade there, now. At the time, I had a knife witha 3" blade and the fellow laid it across the palm of his hand and said that, since it was less that the palm-width long, it would pass. He said that his palm was 3 1/2" wide and that the law was 3". Kinda horseback, but it worked back then. At the Archives Building, the guy just looked at my Delica in the basket, said "Nice knife," and waved me on through. Again, though, that was pre-9/11/01. Everything is a Hell of a lot tighter around DC now, especially when the threat level goes from Yellow to Orange.