Hi all, I will be taking a trip to the states for roughly a month. I currently reside in Asia. I want to be able to use my own smart phone while state side. I have heard about people buying sim cards off ebay, then going to an ATT store and buying a prepaid plan. How exactly does this work? Do I need an unlocked phone? I know that unlocked phones are illegal in the US, but legal if they were unlocked overseas.
I have no experience in this area, guidance is needed : ) I'd rather use my own phone than buying a go-phone.
Thanks in advance.