This is more of a service question vs an iPhone question, but maybe some of you can answer my question. I currently have an iPhone 4S with sprint. I live in NYC and I'm going to Canada this coming weekend. I need to still be able to have service, but I don't wanna be charged up the ying yang for roaming. What's the easiest and most cos efficient way to do this? If I turn roaming off, will I still be able to have service and not be charged? Thanks for the help.