Buy a prepaid "SIM" on ebay, it will already be activated. You can add time on the net or calling in. You can even buy the cheapest time on ebay, they usually just email you the code #. No name or registering required. Tmobile is good as their time lasts longest , is cheapest and they will let you change the area code to one of your choice if you do not want the one the SIM was activated with. (Just tell them you bought the phone on ebay)
Mskr dure you get an ulnocked phone or one that was locked on the network you intend to use.