Sign of the times
Mobile phone maps have guided people through streets and alleys around the globe. But when those people step into a sprawling building, they can get lost.
Inside, people have to ask strangers for directions or search for a directory or wall map. A number of start-up companies are charting the interiors of shopping malls, convention centers and airports to keep mobile phone users from getting lost as they walk from the food court to the restroom. Some of their maps might even be able to locate cans of sardines in a sprawling grocery store.