It’s coming. Indoor location, which has been stymied by the limitations of GPS and lack of mapping, is finally getting some legs and is heading us towards seamless navigation. A shopper is guided from home to an empty parking space at the mall, and the navigation doesn’t miss a beat as he heads inside and gets directions to a particular store, and perhaps to a given shelf. Today, the location of a wireless device usually cannot be determined more precisely than the building it is within. In tall or sprawling venues like arenas, malls, dormitories, or apartments this is a critical problem for emergency personnel trying to locate a person who has dialed 911. Mobile marketing and social network applications have also been constrained by problems in obtaining indoor location.