Stupid noob question. Does the iPhone 3G activation lock the phone to a specific SIM/Number? My little brother is asking me if I can add a line for him on my current ATT plan, and since the new line would be eligible for the 299.99 price for the iPhone 3G, I'm giving it some serious consideration. I'm thinking that I could add the new line, purchase the iPhone 3G with the discount on the new plan and just give him my old phone and stick my SIM in the iPhone. Is this possible or the activation they do "in-store" lock the phone for use with one SIM only? Any help with this is greatly appreciated.