Okay, this might sound crazy, but I have an idea. There is a product called Skyroam which allows you to use it as a 2nd sim card for your single sim iphone/ipad/android device. It uses a Bluetooth connection so it does not have anything to do with any baseband or any locked carrier. If your like me, you purchased and iphone 4 with ios5 pre-installed. So, I am stuck on 4.11.08 What my idea is to use my old cellphone with a Bluetooth connection that can use my T-mobile sim. Any idea on how I can do this?