With ATT, I currently have 4 lines (1 primary line, 3 additional lines on the family plan - 2 are iPhones, the other 2 plain cell phones. Neither iPhone is eligible for an update until next May 2011. Both plain cell phones ARE eligible for updates to the iPhone, with discounted pricing. I want the new iPhone 4. But I don't want to pay for 3 iPhone data lines every month. My question is this - Can I upgrade one of on my additional lines, to get the new iPhone with discounted pricing? And then simply use that iPhone 4, and put my iPhone 3GS in a drawer? And thus, I would have only 2 iPhone data plans to pay for every month, and still 2 additional lines for $9.99 each. I called ATT and they said that yes, this was very possible. However I worry that since I have made a 2 year commitment to ATT for the data plan on an iPhone, that while I may indeed get the discounted price for upgrading, I'm going to have to continuing paying for that "old" iPhone's data every month, and so wind up only using 2 iPhones, but paying for 3 every month. Anyone able to clarify how this works and if it is indeed possible?