Hey guys. I was wondering if I could get some help with my current situation. I am going to be getting the iPhone 4 and right now I have a 3g. My wife uses a BB Pearl and was thinking about coming over to an iPhone. I told her that she could use my 3g once I get a hold of the new one just to see if she likes it. My question is can I just swap out her BB sim into the 3G? We are on a AT&T family plan, don't know if that makes a difference or not. Would we have to contact AT&T for the switch and would there be any charges? Hopefully it won't be too much of a hassle. Thanks for the time guys and appreciate it.