Accelerometer/Sensor Information and Profiled Path
Good for metro only. Low accuracy. May require data connectivity.
Can be very expensive to set up. Very accurate (depending on setup).
Can be expensive. Accuracy depends on implementation.
Wi-Fi Positioning Systems
Requires profiling of area (profiling can be inaccurate depending on factors such as time of day, changes over time). Requires data connectivity and database server. Medium accuracy. Widely used. Doesn't work where you cannot profile the access points against known positioning (GPS).
iBeacon - http://en.wikipedia.org/wiki/IBeacon, uses bluetooth. Lower range, can be used to calculate position, requires database connectivity, designed to be context aware rather than used for positioning.
Blue-Dot - http://searchengineland.com/aruba-networks-enables-blue-dot-indoor-navigation-beacons-209405, similar to iBeacon.
More technologies listed here - http://en.wikipedia.org/wiki/Indoor_positioning_system