WHITE PLAINS, N.Y.—Starwood Hotels & Resorts Worldwide, Inc. (NYSE: HOT), an on-going innovator and leader in the digital space, today launched a new digital extension to their award-winning Starwood Preferred Guest® (SPG®) loyalty program by tapping into location-based social networking. Starting today, guests can earn valuable Starpoints® and Free Resort Night Awards for foursquare activity at Starwood hotels and  ....