i am new to apple and the iphone. i purchased my iphone and switched to att may 22, 2009. i have been told that i can go to best buy and just trade in my phone for the new 3gs since its within 30 days but i am worried about being able to get one friday because of high demand. should i expect to have to be at the store at opening to be able to get a new phone. i just dont have much time to work with since my 30 days will be up on the 22nd of this month. any suggestions?