A great article from Harvard Business Review:
Once upon a time, there was a country where bankers disappeared. The bankers, fed up with regulation, dissatisfaction, and downright hostility, decided to unleash the planet-destroying superweapon in their arsenal: they went on strike, not once, but three times. … This is no fairy tale, so we don’t have to imagine what happened next. And what did come next was something really, really interesting — and just a little bit awesome. Instead of Ragnarok ripping prosperity to shreds, the economy continued to grow. Though the money supply did contract sharply, neither trade, commerce, nor industry came to a grinding halt. How? People created their own currencies, to substitute for the collapsing money supply. They kept using checks to pay one another, but then, people’s checks began trading within communities. Here’s how Antoin Murphy, one of the few scholars to have studied these strikes, which took place in the 1970s, describes it: “a highly personalized credit system without any definite time horizon for the eventual clearance of debits and credits substituted for the existing institutionalized banking system.” The country in question was Ireland — today, in deep crisis because of profligate banks.
I recommend the whole article.