Switching to the Un-Carrier can be exciting, but you have to know how to get set up. Here's how to activate a T-Mobile SIM card.

Regular and Micro-SIM cards are too big for the iPad or iPhone, but this trick enables you to cut down a SIM card to a Nano-SIM so it fits into an iPhone or iPad.

Find out how to trim your own micro-SIM card for use in phones that require this new format.

If you want to upgrade your iPad to have 3G/4G capabilities, you need to equip it with a SIM card. Our beginners' tutorial explains where to get the right SIM card, and how to do install it.