Earlier this month a tipster claimed that he received a huge roaming bill from T-Mobile despite taking precautions. Now, T-Mobile has offered an official response—some of the apps can turn on data roaming by themselves.
T-Mobile is committed to delivering the best experience in wireless to our customers. If a T-Mobile customer would like to use their T-Mobile G1 while outside the country, they should contact Customer Care before they leave to ask that the WorldClass feature be added to their service at no additional charge. If they choose, customers can also disable data roaming on the G1. This can be done by going through the following steps: Home Screen > Menu > Settings > Wireless Controls > Mobile Networks > Data Roaming.
Some third party applications available for download on Android Market require access to the internet and have the ability to turn on data roaming when in use. Customers are informed whether an application will use this feature prior to downloading, but should also be aware when travelling outside the country.
So there you have it. Apparently, if you want to travel abroad, it is imperative that you delete any applications with this issue. It may also be one reason why the battery life is so poor. [Engadget]