Coin, the latest clever payment system, shows that digital wallets remain a terrible idea

Today a new startup, Coin, launched with an intriguing product: A battery-powered, credit card-sized device that stores all your credit card information in one place. Perhaps intentionally, it looks a bit like the heavy, exclusive black Centurion card from American Express, but with a small LED display. You simply tap a button on Coin and cycle through the cards you’ve stored on it. When it shows the one you want, you swipe it like a regular card.