I am purchasing a used blackberry Curve 8330 from my cousin and was wondering if i could use the SIM card from my old phone on it? i have an AT&T SIM card and use it on an AT&T phone? Can i take that SIM card and put it into a Blackberry Curve 8330 thats locked to sprint? is there a SIM slot to put it into and is there an easy way to use it on the Blackberry?