I just signed up for MobileMe 60day trial two days ago, then last night I finally got 2 iphones and purchased the full MobileMe (boxed single user) at a discount from the Apple Store.   Can I use the serial# that comes in this box to UPGRADE/activate my current Trial account?   Also, if I decide to upgrade to the family account later, will I have to pay the balance of $149 (-70 = $79)...or a only the set difference in price between the two plan levels ($50).  If it's the full balance it would be like I never got a discount in the first place.  Thank.