[Bossman]

It depends on what sim card you want. For AT&T and Tmobile you can get them on ebay or walk into a store. They may even give it to you for free as long as you add credit to it right there. For sim cards in other countries, you can do the same. Walk into a store and get a sim card that suits your need. You can also get them on ebay. Heck! In some countries you can get sim cards from the street vendors, at the airport and in vending machines.