I admit I'm a new (uninformed) iPhone owner. I paid full price at an Apple store for a 3G, 16Gb phone without getting it activated. I already have an ATT sim/account for an earlier phone (not iPhone) without any data plan. I just had the iPhone unlocked/jail-broke so that i will be able to use it in Asia with Asian sim cards. Now my question is: if I put my ATT sim card in my new iPhone now, will it trigger a monthly data plan charge to my account?????