on 26-07-2013 12:04
Its automatic, but you can only use credit abroad, and it can be expensive Try to use wifi whereever you go to help your credit balance, and make sure you have enough credit to last you
on 26-07-2013 12:05
on 26-07-2013 12:30
Depends on your phone I think, but on mine (iPhone 3GS) I always make sure it's OFF actually, as it really adds up fast and you'll end up using all your credit really quickly if you just leave it ON.
I'd use free wi-fi as much as possible and then turn roaming ON as and when you need to and have no other options.
Have a good time abroad!