Companies like Facebook and Twitter have redefined social interaction. But what if “machines” like automobiles, bicycles, health monitors, appliances, instruments, and anything else you can connect to the Internet, could all become members of your social network, collect data you care about, and feed it back to you at just the right time? Nike+ is already doing this for your body, but every major industry, from healthcare to cars to home construction, is now building sensors and digital...