[Idea] Restricting data usage via APN info toggle
The iPhone is pretty data happy: it's really designed with an always-on internet connection, whether from wireless or GPRS/EDGE. However, there are plenty of iPhone users who have an unlocked iPhone, and happily use it on wireless, but balk at current data prices.
For myself, I am on T -Mobile in the UK, and I simply haven't put in any details for the T-Mobile APN, internet settings, etc.: I'm simply too scared that if I do, the iPhone will simply make regular use of the GPRS connection whenever it cannot find wireless, and I will get stuck with a huge bill.
However, there are cases where, in an emergency, I *would* actually want to use the GPRS!
I'm assuming the APN settings are stored in a preference file somewhere. So I'm thinking... maybe it's possible to write a little program (by someone who knows how rather than clueless me) which simply swaps the file with one you prepare earlier. I.e., one file has all the settings in, the other doesn't. The one with no settings in is used by the iPhone by default. When you want/need GPRS, you flick the switch (like in the Services application), and it swaps the empty file for the one with the settings in and you can use GPRS. When you're done, yoou simply flick the switch, the process is reversed, and your iPhone is cut off from GPRS again, giving you peace of mind that you're not running up huge data charges...
What think you? Or has this already been thought of and implemented? I haven't found it if so...
