questionnnn

im looking into getting the iPhone 4 from att. My phone isn't up for an upgrade yet, but another line on my account is. my question is, do iPhones have SIM cards and can i place mine in the phone so that i still have my phone number and not the other persons number which i technically bought it...

im looking into getting the iPhone 4 from att. My phone isn't up for an upgrade yet, but another line on my account is. my question is, do iPhones have SIM cards and can i place mine in the phone so that i still have my phone number and not the other persons number which i technically bought it...

if i get it and used it on my fone, will the touchscreen still function through the protector??

How are my friends talking to me on the chat box when I never even added them? Please help?