Who might run the show in a post-cash world?

Is cash on the way out? In my own daily routines, I find myself using coins and notes less and less, to the point when I am often stuck for a pound coin to use the lockers at the swimming pool, or I audibly ‘tut’ when shopkeepers tell me there’s a charge for using my card. I just don’t carry cash very often. In fact, I don’t even physically use my debit card very often. I’ve got so used to...