i was talking to a former work mate today--his 7 year old had gotten his phone--knew his password--and played games on it. Racked up a bill of £90. Daddy wasnt a happy bunny!
Personally I don't consume much information on the phone, unless you count checking the bank regularly, I don't consume because I hate reading on a tiny small screen format it's not fun. For me the phone is about messaging the kids, the bank, low grade photography (data recording pictures of invoices and the like) sending money simply as it is easier than the same operations on a desktop or laptop computer and occasional navigation, oh and it is also a pocket calculator as I have an HP 42s emulation on it, a calculator that has no equals button, I hate the equals button it is totally unnecessary RPN all the way ( Reverse Polish Notation) I learned RPN when I was 14 and I've never used an equals button since or brackets for that matter But yes the phone is your enemy, back in 2006 my phone at that time decided to stay on in navigation mode using map data from the web while I was in Metro Manila, however it was roaming on O2 at the time, I had deliberately to my mind turned off the navigation app we were travelling from Malate to Caloocan and the amount of data it consumed landed me with a 1600 quid bill, lesson learned. I don't think you need the minimalist approach these guys are on about but a lot of people are so immersed in consuming media on their phones that it is not bad advice, I won't even view this forum on the phone as I find it too awkward. edit: algebraic logic with brackets is horrible RPN is elegant.
last time my wife went home she thought her phone would connect to the planes wi fi--it didnt. She quickly used up her monthly limit in roaming charges--£20. I complained to tesco mobile--who knocked £15 off the charges.
I was refunded, by T-Mobile, years ago, all the local charges imposed by the local SPs, for the welcome texts received during my travel to the Philippines and the ones in Doha.