Spare Pair of Boot Laces (160cm)
Obviously, their primary use is to replace worn bootlaces, but these lace cords also come in handy for other practical things. For example, if you wear a rain poncho and it is very windy, tie the boot laces together and wrap it round your waist. It stops the poncho flapping around you.
They can become a spare washing line when there is nowhere to hang out you wet clothes.
They can even be used to make a splint in the event of injury.