I'm very new at this, so forgive me for stupid or repeated questions. I have a 1G iphone that was jb without sim. I disabled data roaming but cant turn off all cellular data and 3g because this options do not exist on the os that is installed. The problem is that I only use the phone on wifi, but sometimes that goes off and it starts costing me a lot of money! I called the phone company but they can't disable internet usage manually. So I have to do it on my phone. Is there either a way to load another os without loosing data (even thought the phone is jb) ? Or is there another hack or something how I can turn off cellular data and 3g. Thank you for your help!!