Yesterday Pocket-lint highlighted a potential problem where apps and music could be downloaded automatically via 3G and result in your exceeding monthly limits. The consequences when roaming abroad could be ruinous. Now the article has been updated and, while the problem is not as serious as first thought, the set up procedure is misleading at best.
In general, download settings could do with attention. There are a number of automatic functions (such as app downloads and frequent mail access) that make sense when on home turf and playing with a monthly allowance of 500MB or 1GB. But when roaming (for instance, when using Vodafone’s excellent £2-a-day-for-25MB European package), it is vital to remember to adjust settings. Use of cellular data for downloads should be turned off and my suggestion is that push mail be switched to manual.
Ideally, it would be good to have one button, similar in universal scope to the Airplane Mode, that would alter all the settings necessary to restrict 3G downloads. Since the main problem lies in overseas costs when roaming, I suggest the Data Roaming button (Settings, general, network) should default to a minimum-download state when switched on.