In reply to Si Withington:
A Swiss Army Card?
I was given one as a stocking filler a few years ago and thought at the time "can't see that being much use but thanks" (I'm obviously an ungrateful git). I was very wrong.
It now lives in the lid of my climbing bag and has been very useful on numerous occasions. It weighs nearly nothing, is the size of a credit card and has sorted out broken nails, splinters, removed ticks (a tick card is better but I didn't have it with me), cut tat, trimmed plasters and dressings, got rid of threads and frayed edges. The only thing it has let me down on is opening bottles of beer!