A friend is giving me her Iphone 4 I have a pantech impact with a regular sim card i heard about trimming your sim card but that just seems to risky for me... Will att be able to transfer the information from a regular sim card to a mini? if so will they charge me for the new i phone 4 sim card.. Will they charge me a transfer fee? Will they even do it? if so im on my grandparents plan would i have to have there account information and what not?