An upgrade of Google’s mobile mapping service released Tuesday includes directions within stores, malls, airports and transit centers in the U.S. and Japan. ...
If the floor plan is included in Google’s index, the software pinpoints a user’s location with a blue dot. The user can then figure out where the nearest bathroom is in a mall or find an airport’s gate for a departing flight. The software is programmed to automatically change to a different floor in a building when the user does.
Big Box stores like Home Depot and Ikea are in as are 18 U.S. airports. The service uses wi-fi to locate users, but I would not be suprised if NFC is not used soon (APB coverage earlier this week).
There's been a bit of a push toward better indoor mapping and location detection in recent weeks as we discussed on a podcast this month.