My mom is traveling to Canada next week and is worried about the possible charges she could incur. I've never traveled out of the country with an iPhone so I'm not much help. I've read several pages on the AT&T website and have read several threads here at MR but I still don't feel comfortable. She's fine with just using WiFi so she doesn't need an Intl data plan or anything like that. Will turning data roaming off and not calling/texting be enough to avoid a huge bill? I've read online where people had it off and still had huge bills. Enabling airplane mode and then enabling WiFi would have to keep the charges off, right? This has to be the safest bet. What about the option in iOS 4 to disable cellular data? Would that be a safe bet? Does that kill the phone and data or just the data? Any advice would be appreciated.