What application is at your mind?
The main options are:
1. Network based (or signal based)
2. GPS based
3. WiFi based
As you ruled out 2 and 3 and you have no access (I hope so) to the inside information of signals of any given provider, you are out of luck I would say...
(Read more about phone tracking here:
http://en.wikipedia.org/wiki/Mobile_phone_tracking[
^])