Even if cingular and sprint were on the same frequency band, the phones would be locked. so u'd have to use some black-market software to do it anyway.
the best way to tell
GSM from the others is that it won't have a D for digital on the screen, because it's always in that. Also it has a
SIM card of u take off the back and sometimes the battery.
Also a
CDMA phone (like sprint or verizon) will usually have a pull-out antenna. why do u suppose that is......... lol