I picked up a Sterling Knife Sharpener the other day. It cost me $13 bucks and change. The purpose for the sharpener was to have something for the field that I can use in case my knife becomes dull and I need a quick edge to complete whatever task is at hand. I tested the sharpener out on one of my more dull knives and I was impressed. I was able to put a sharp enough edge that I could shave hair off my arm. Not bad for a cheapo sharpener. The best part is it's made in the USA. Pick one up for your key chain and your BOB.