Long story short, I got my i4 on that Wednesday preorder, i bought her a 3gs on memorial day.. so a month ago today from radio shack. Once i got off work best buy was sold out again. If she wants to take her phone back it has to be today. We have 3 lines.. my original line, her old line that wasnt up for an upgrade till 3/11 and the new 3gs line we oepend...it was cheaper to leave her line dormant instead of pay the $125 etf.. So i told her she could take her 3gs back and get a crappy go phone or somehting and whne next stock coems in ill swing by anywhere and get one... she is on the radio shack list anyway... So 1. question is is does that work with the go phone can i swap sims? ... 2. If i swap sims will she loose her unlimted data? Or could i switch it to the dormant line andelave it theer and then switch it back with the i4? 3. Or how long does she have ot have it before she can sell it and then just pay the etf on the old line and open up a new lien, then still have 3 lines as dumb as that sounds Thanks in advance!!