I would recomend either Tmobile or Verizon, depending on how much time they would be using the phone and whether or not htey would be leaving large metro areas often. If they will be using lots of minutes and will stay in larger cities, Tmobile is great and very cheap, if they will be using the phone very little, and want better coverage in more remote areas then Verizon can't be beat. A prepais phone may also be a valid option if they really aren't going to use it much, they don't cost much to buy, but the minutes are about .25 cents each. For Prepaid I would recomend Tracfone, they use other carriers to provide thier service, like Verizon and Cingular, so thier coverage is second to none, I believe that they also recently stopped charging extra to make out of area calls as well.