A few weeks ago, I spent a night at the Kendall Hotel in Cambridge, Mass., a congenial place done up in a firehouse theme with an atrium on the top floor. There’s a bowl of apples in the lobby, free ...

If you don't know what we're talking about, go to your bathroom drawer now, turn your toothpaste over and look at the marking on the rigid part at the bottom of the tube. You'll likely see one of four ...