To support iPhones and iPods, you'll very likely need to join the MFi program. Why not use GPS? The main problem to solve would be creating a database of the

To support iPhones and iPods, you'll very likely need to join the MFi program. Why not use GPS? The main problem to solve would be creating a database of the location of each store in the mall. Did you find that there isn't enough GPS coverage in malls?