Ooooh, something I can relate to..
Phones is a big deal in America, as you want to keep in contact with people while you are away.
Two best things I did, was buy an international calling card, which is cheap, cheap calls overseas, to talk to friends and family back home. And I also bought me a mobile phone, mainly to use to contact other mates on camp, for nights off and post camp shenanigans. I opted for something called a Tracfone. Basically, you buy the fone (choice of a cheap nokia, half decent motorola etc, depends on prices) and you activate it (give it to the guy behind the counter and get him to do it all, saves you a lot of time) and away you go! Instead of buying credit, you get "units", where 1 unit= 1 minute calling time, txting is 0.3 units. Recharging is cheap, and you get a good deal of reception, I did on camp in Maine, and its still going strong all around the states. Wal-Mart sell them, but I generally found Radioshack to be a whole heap cheaper, and they are nicer there.
Yay for first hand experience.
"It's the kid inside of us that keeps us all from going crazy..."