I currently have the Samsung galaxy s3 activated on my account. If I were to buy a used iPhone 4 could I, every few months or so, switch between my iPhone and my galaxy? Just to Switch things up and prevent myself from getting bored with Either phone. I'm wondering if there is a certain amount of times you can activate a phone on a specific account. And what process would I have to go through every time I wanted to switch between the phones. I understand that each phone uses a different sized SIM card. Would I need to buy a nano SIM card for the iPhone and then an adapter to use it on my galaxy? Is it even possible to just buy a SIM card? And being that I wouldn't be using the original SIM card that came with my galaxy, what information would I lose? Thank you!