"Know what method your carrier uses to fix location. GSM phones (AT&T, T-Mobile) use radio signals to triangulate your position; climb to high ground to reach more towers. CDMA phones (Verizon, Sprint-Nextel) use internal GPS receivers; find an unobstructed view of the sky and wait a few minutes for the phone to lock on to satellites. Smartphones (BlackBerry, iPhone) combine both methods for the most accurate position. "

Thats not accurate either. I've found that make and model of phone will use different methods but most anymore have some kind of gps chip combined with the agps trangulation, its not on a per carrier basis.