Developing mobile applications for location based services (LBS) is a challenge.
If developing for Android or BlackBerry you have a great IDE (Eclipse), but there are many traps you can tap in developing LBS Applications.
I'll give you some hints what you have to watch:
* GPS or Geolocation
* valid Coordinates
* Waypoints, Tracks and Routes
* mastering KML at mobile device
* providing KML Services via OSGi and JAK at server
short demo how EclipseRT (Equinox, Jetty) are used as an easy to setup server to provide LBS services to different mobile platforms