I think I'm going to jailbreak my iPhone 3G ( 2.1 ) tonight, but I have a couple of questions first. I know I should first backup my current iPhone and save the backup file somewhere safe. Then after I've jailbroken the phone, can I restore that backup and my phone will still be jailbroken, or should I start as new phone and just resync? If I decide to undo the jailbreak, how can I get it back to normal? Can apple tell if a phone was ever jailbroken in the past?