How to create a GPS application on Mobile phone?

Question

For a GPS application,

1) If say the GPS application is used inside a building, I would like to know how to define or create the map ourself ? Usually the map is provided by the vendor and the map is showing the roads(big scale) if compare to inside a building(small scale).

2) How do I map the position that return by the GPS receiver into my own created map?

Is there any open source framework available for GPS application that running from the mobile phone?

Answer 1

A GPS doesn't work inside a building.
But this is perhaps a place to start if you want to work with gps and windows mobile.

"GPS Tracking with Windows Mobile 5.0+"