If you're worried about accidentally leaving on what you're supposed to turn off, then why wouldn't you be worried about accidentally leaving off another setting you're suppose to turn on to be sure the first setting is turned on?
Originally Posted by
milepig
Am I missing something obvious?
Turn off roaming (but you might turn it off)
Remove the SIM (but you might forget)
Turn off your phone (also might forget)
Throw the phone overboard!