I have an iPhone 3GS (4.3.3 - 8J2 ... max iOS version that was jailbreak compatible). It's jailbroken and running a GoPhone SIM card on a $2/day plan...no data. I recently got the chance to pick up another guy's used iPhone 4. Question: How do I move my GoPhone account from the 3GS to the 4? My research indicates that all I should need to do is use a sim cutter to reduce the SIM card's size, insert and enjoy. After all, when I got AT&T to move the data from the GoPhone SIM onto a standard AT&T SIM, all I had to do was insert the SIM and turn on the phone. However, I was required to jailbreak the 3GS to make a GoPhone account work, I don't know it it is required on the iPhone 4. Nobody is indicating that it needs to be done, but nobody explains why the difference.