I started doing some thinking about creating an Android application that can be used within a corporate building to determine what room you are in. Obviously I\'m thinking GPS a
Perhaps it is not too much help but the papers I have found on this subject are these:
RSSI-Based Indoor Localization and Tracking Using Sigma-Point Kalman Smoothers
Pedestrian Tracking with Shoe-Mounted Inertial Sensors
Enhancing the Performance of Pedometers Using a Single Accelerometer
I have no idea how these methods would perform in real-life applications or how to turn them into a nice Android app.
I am curious what other answers you will get.
How about bluetooth tags that emit a room id. You could make money merchandising the emitters on a facility size basis and they could provide additional functionality such as:
(1) forming a pico net that ultimately updates the an onsite server with locations of everyone using the app, or
(2) tracking key equipment with a similar bluetooth tag, etc.
You could get something similar to the link below in qty from China, I'm sure:
http://www.engadget.com/2009/03/26/nio-bluetooth-security-tag-keeps-tabs-on-your-belongings/