mauried:
Extremely unlikley, as its the SIM card that contains the data needed to tune the radio to the correct frequency for the relevant carrier.
Unless you can somehow hack the radio in the GPRS module to control the tuning.
If I did activate the sim card how hard would it be to write the exact operating band and signal strength to a lcd shield? And could I "listen" to more than 1 850.xxx mhz band at the same time?