On a family plan, I'm primary my son is secondary w/ a $150 + bill for both of us for a LONG time. Bought an i1 June 2007, upgraded to a 3GS last August & renewed my contract then. My early upgrade is right in line w/ the 6 month reprieve many are discussing, March 2011. Before then I would pay $399. Son is eligible for the upgrade @ $199 on 24 June but he is using a go phone for a variety of issues, not going there. Was told by a fairly competent AT&T employee that he has done a number of cross upgrades for 3G & 3GS customers & THINKS he can do the same when the 4th Gen comes on line. I would receive the i4, my son keeps the go phone but has incentive to earn my 3GS down the road & ditch the go phone. AT&T fella mentioned the micro sim in the i4 vs. the go phone sim, can someone explain the logistics of a cross upgrade?