sprint phones have GPS, my old Sanyo 8100 Picture Phone had GPS, and my current Toshiba Pocket PC Phone has GPS. Wifes LG Has gps, just about all the new phone have it now.
Unfortunately, just because they "have GPS" doesn't mean that the phones have a way for a developer to access the data. I could be mistaken but the currently available Sprint phones only use the GPS internally for E911 and location based services (nearest movie theater, etc)