The barista swiped my card, and then looked at it, perplexed, turning it over in her hands. The Stratos Card is the only credit card you'll ever need---supposedly.Stratos Down an alley just outside the WIRED offices in San Francisco, Darwin Cafe is one of those coffee shops that gleefully resists technology. The place runs on an old-fashioned register, with big keys that thunk and a drawer that ka