Let’s say you are traveling with friends. You’re in Prague. You’ve enjoyed an amazing dinner. Only crumbs are left on the dessert plates and the espresso cups are empty.
The waiter lays the bill on the table. Your friends exchange glances. What happens next?
Thirty years ago, you all would have fished out the vinyl wallet containing your American Express Travelers Cheques. You would have calculated your share, signed several $20 checks and handed them over.
Twenty years ago, with th...