Originally Posted by tsac
Swapping the SIM will only allow the phone to work on the BB. He will need to do a data plan and talk to someone. Cingular wont allow a simple swap. Also if on a corporate server, it will ask if you want to change PIN's then ask for the email password. If it was as easy as swapping SIM cards then no one would buy a data plan.
The OP mentions swapping SIMs and adding a data plan. I wasn't saying that you don't need a data plan, simply that you don't have to call GSM providers to "activate" GSM phones.