Coming back to my roaming requirements for this part of the story, it's not only important that the web browser and the e-mail application require as little data as possible but also that Android itself is not chatting with the world and thus incurring cost. So to see what Android does, I installed "3G Watchdog" and let the mobile run overnight with Opera Mini being executed but the e-mail program shut down. Good news here as well. As I don't have any active widgets, instant messengers or other programs running that could exchange data in the background, the watchdog counter only recorded around 4 kilobytes of data exchanged. It would be interesting of just what those 4 kilobytes where but I'll leave it at that for the moment. From a roaming perspective that's quite acceptable. In other words, Android has passed my roaming data test as well.