AGPS uses a reference GPS receiver in each tower that sends SV data to
the mobile handset. The handset does not have a full GPS installed;
instead it uses the SV (space vehicle, e.g. the satellite) data to receive the time pulses from a single SV and sends the time delta to the tower. The tower is then able to compute the position of the phone via a differential calculation and log it for E911 compliance. It is typically accurate to 100m indoors and
15m outdoors.
this means if your cell phone processes agps signals you still can't use location data unless the tower transmits that *back* to you. unless of course the phone itself has a receiver and processor built-in to calculate the position.
I won't be waiting for t-mobile to release agps services / data anytime soon.