Ha tracking.... they got that wired. Last winter we flew these guys to mtn sites while they built the system for a major western US mtn market. We were also involved in the testing/proving/trouble shooting for the sites. It is mandated that the phone companys install this by 2010 or something. It is already up and running in NYC, LA, Most large eastern seaboard cities, interstate highway corridors and a few markets in the west.
Basically they can pinpoint anyone with a turned on cell phone to less than 10m. It was designed for 911 applications. If some one calls 911, all the other cell sites go into some kinda of dme mode and send signals back and forth, pinpointing the cell phone. They claim 100 meters but during the tests the guy was a few meters off with gps cords!
Just think of the big brother applications of this thing. the sick thing is the story I heard was it was someones grad project and it had to do with a dating service!
check it out
www.trueposition.com
rb