Every so often a lemon, and sometimes various kiddies' stuff (mind you, they are 16 & 18 yrs old...) I too always carry a penknife, a carbon-blade Opinel (medium-size) - not so much for self-defence, more for feeding opportunities. (Once I unofficially won an oyster-opening contest with it, while the other contestants toiled away in silly chainmail gloves and with special oyster-knives... You can't beat a good Opinel! )