Sure, GPS helps us get from Point A to Point B, but what if you're just trying to find the Cinnabon? A new system from Fraunhofer allows for in-store (or in-mall) navigation and uses very simple sensors to asses where you are in the building at any time.
The system works when you enter the edifice and scan a QR code. This identifies your current position. A built-in pedometer and compass assess the speed and direction you're going and, rather than relying on GPS signals, the system can tell where you are simply based on stride length.
The system, called the MST-Smartsense Sensor, has its own processor built-in and could work with nearly any mobile device including tablets and smartphones. Although these things are proof-of-concept right now, it seems that something like this would be quite simple to implement using any modern phone assuming it had a pedometer built-in. Regardless, look for it at a defunct mall somewhere near you soon.