An inventory for a trip to a tropical beach could read like this: Swimsuit, check. Sunscreen, check. Passport, check. And iPhone, check. Well, make that a possibly giant check, drawn from your bank account. Unaware travelers can blithely rack up eye-popping bills on their iPhones while traveling abroad. The international roaming calling rates are bad enough, but data usage is what really delivers the sting. The root of the problem is that the iPhone, with all its apps, positively inhales data.
