I have on my keychain the same p-38 I've had for 20 years. Its been used to open cans, boxes, cut down a piece of bamboo, turn screws, pry, and in a pinch strike a fire steel with it. I've got a spare that is the same vintage (from when my dad was a boy) that I have thought about putting on my keychain instead because I put a small crack in the hole for the keyring, but haven't gotten around to it... the crack happened 10 years ago using it as a screw driver.