iPhone travel apps could cost you thousands in data usage fees

To the shame of many short-sighted iPhone app developers, many budget travel apps have an enormous flaw. This fatal issue could turn a 99-cent app intended to save you cash into a nightmarish drain on your cell phone bill. The problem: Many travel apps require a data connection to work.

When I'm shopping for apps, the first question I ask is: "Does the information it needs live on my phone?" If the answer is no, and if the program requires a network connection to deliver results to me, it's out. Domestic data usage is included in your plan, but international data usage, including in Canada, Mexico, and just a few miles offshore on ships, is head-spinningly expensive. You'd be alarmed if you knew how many travel apps require data usage as part of their structure. Turn off the data network, and the app becomes useless.

AT&T unhelpfully lists the roaming rates as "$.015/KB in Canada; $.0195/KB the rest of the world." What does that mean in practical terms? How many KBs will you use trying to find a local cab company or calling up the correct Italian pronunciation of "Check, please"? That's anyone's guess, since apps don't tell you how much data you're using as you use it. And it's how customers have come back from European trips with $3,000 phone bills, based even on curtailed data usage.