Been searching, but ended up with outdated or conflicting info, so thought I'd just try here: We've got 3 lines on AT&T's FamilyTalk plan. MomInLaw- 3G in another state - eligible for 4S upgrade discount. Wife- 3G - eligible for 4S upgrade discount. Me- iPhone 4 - not eligible until March 3 What I'd like to do is buy two iPhone 4S devices using the discounts available for Wife and MomInLaw, then give MomInLaw my iPhone 4, Wife and I getting the new iPhone 4S. I've read this morning about IMEI switching, and SIM card switching, but it's not at all clear whether this can be done. If this can be accomplished, what steps are necessary?