Activate your iPhone back to AT&T if the SIM card you insert after you install blackra1n onto the device doesn't work properly. Blackra1n is a third-party program that "jailbreaks" SIM-bearing iPhones ...

If you've just got your hands on a shiny new Sim card, congratulations. Switching your Sim (the chip that dictates your allowance) can unlock huge savings. Now comes the crucial step of activating it ...

Changing carriers can be exciting. You might get to pick up a new phone, or maybe you want better coverage in your home area. Either way, you have to know how to get set up. Each carrier tackles SIM ...