In my short time caching I have never encountered a situation that I couldn't get out of quickly. However, that doesn't mean I shouldn't go prepared.
I always carry my trusty Glock 19 with a couple of extra mags in either a paddle holster or small-of-the-back. I have been licensed to do this since I was 21 so this is not anything new to me. Recently I have also been carrying a fixed blade knife having been trained in it's use as a defensive weapon as well. These are merely precautions and tools for defense. Nothing more. I hope to God I will NEVER have to use either one.
Before I started geocaching I carried most of this stuff around with me anyway. It is always better to be prepared.
My 2 cents. BTW...Hi, I'm jpthegeek.