I’ve been at some festivals where the bartering system was alive and well! People would trade beer for camping chairs or a volleyball for some duct tape. Good times :)

Not 100% true: I know some places in Norway that have unreliable internet connectivity. They have terminals in the store that will save your purchase and wire it to the bank when connection is restored. Of course, this means you can over-draw your card, but I’ve never heard of that being a big issue in those small places.