I need to switch the number attached to my brand-new iPhone4 without actually switching the phone itself. Does anyone know whether or not this is possible?  When I purchased iPhone 4 from an AT&T retailer yesterday,they opened a new phone line to attach to my new iPhone. They were supposed to transfer my old AT&T number, which I’ve had for six years, onto my new phone. I hadn’t upgraded since 2004, though, and my 2g plan was incompatible with the new 3g technology, so they couldn’t figure out how to migrate my number over to the 3g network and subsequently, to the iPhone4. I accepted having to get a new number because I thought it was the only way I could use the new iPhone (not to mention that I’d been waiting in line since 5:30 am and got the last phone in the store).  Later on, I found out from AT&T Customer Care that the store could & should have moved my original number over. They also told me it’s possible to fix this: cancel the new iPhone line and migrate my number onto the 3g network, then onto an iPhone. Customer Care said that AT&T has a “Buyer’s Remorse” policy where you can cancel your contract within 30 days without paying the early termination fee. There is, however, a restocking fee for “returning” the new iPhone4.  My question is, can’t they just move my old phone# over to my same iPhone4 once they close the new line? I am not returning the phone, just applying a new number to it. What on earth does this have to do with “restocking”? Am I really supposed to get a different iPhone4 just to apply my old# to my current iPhone4 sim card? Does Apple have some kind of policy where you the store can’t wipe this phone and reprogram the sim card?  I’m going out of town next weekend and need to have my iPhone with me, and I’m afraid that if, for some reason, they can’t do the simple, obvious thing and just reprogram my current iPhone sim card, I’ll have to wait for a new iPhone4 handset in order to straighten this out. And who knows when they’ll have more in stock (without having to stand in line for hours all over again).  Does anyone know anything about how the new iPhone 4 sim cards work? Is it actually necessary to ‘re-stock’ my current iPhone, or is it possible for the AT&T retailer to just wipe it and re-program it with my original number?  Any advice would be greatly appreciated.  Thanks!