This was probably 23 years ago, something like that. A friend was driving, we were coming out of the community college, got pulled over. I don't remember why. My friend had a "counterfeit firearm" which is like a realistic prop, in the car. He immediately announced its presence and it was taken out, examined, and confirmed as not a real gun. I was asked if I had any thing on my, and I replied that I had a lock blade. This was taken out and put on the hood of the car. One cop's chatting with my friend, the other's with me, and he keeps looking at the knife. It was a Gerber, as I recall, that had a sort of unique lock, a sliding rod that went into the end of the tang when it was open with a sliding control for this on the side of the knife. I saw his interest and said "its a beauty, isn't it?" This started a very nice discussion of knives and my actually retrieving the knife and demonstrating the lock mechanism to him. The knife wasn't really such a beauty but it all went pretty well. I wasn't the one getting a ticket, after all.
The one time in college when I actually did get arrested (trespassing, that was over twenty years ago, too) I didn't have anything but a mini mag light on me... which made them think I was a burgler. Ah well...