We have a daughter heading over to England for Bible school in a month, and it's recommended to get a new sim card when she gets over there, to replace the one in her phone that she has now. But it also sounds like the best way to get use out of the phone is to purchase phone cards.

This is the website for Canada, but I'm sure that it's similar to what's out there for the US.

http://www.travelcuts.com/Essentials/International-Calling-ISIConnect.aspx

Mrs. Dirtfarmer