One of the great mysteries of modern life is the time it still takes for a check to clear. Every other financial transaction is being reduced to the tap of a phone or the press of a key. But checks take days to rumble their way from payee to the originating bank, days of lost interest and presumably fees for the intermediaries passing them around behind the scenes. Transactions and data management are supposed to be slicker these days, and yet time and again all of us run into situations where it’s as though technology never happened, or stopped around 1993.

Now...