Rocket Track - Open source GPS Tracker for Smartphones

Here is an example project with lots of good information.  GPS tracker for finding rockets or other objects.

Xbee communication to object, with GPS on the sending end.  Coupled to a cell phone via bluetooth to display location information on an android phone map display.

http://www.rocketryforum.com/showthread.php?53120-Rocket-Track-Open-Source-GPS-Tracker-for-Smartphones