Applications installed on an Android handset are capable of automatically switching on data connectivity, and roaming, so their owners run up huge data charges.
Several US users have complained of unexpected data charges being run up on their G1 handsets, and Engadget reports that T-Mobile has put out a statement clarifying that applications do have the ability to switch on roaming without informing the user - with the caveat that the user should have been informed of this capability when they downloaded the application.
Of course, not every user reads the small print when downloading applications. They particularly don't read the fine print when those applications come from a marketplace that doesn't have any ability to charge for downloads, as the lack of billing encourages risk-free testing of software. With data-roaming rates still unacceptably high, though, it seems there is a significant risk attached to such applications.
Conversely: many great applications benefit from being able to make their own data connections, and bothering the user each time would ruin their utility. What's needed is something akin to the setting familiar to MMS users - auto-connect when on the home network, otherwise connect on demand.
Given the problem lies in the Android platform it should equally affect UK G1 users traveling abroad, but T-Mobile UK is checking on that for us and we'll update you when we hear from them.
Always-on connectivity is really useful for widgets and other Web 2.0 paraphernalia, but it won't take too many surprise bills for users to switch off the automatic connections - hugely reducing the capabilities of the platform. ®