My dad has an iPhone 3GS and after I showed him my Jailbroken iPod Touch he wants to know if I can Jailbreak his phone UNTETHERED though. I've searched around and some sources say it's tethered jailbreak, some don't. By using blackra1n on his iPhone 3GS firmware 3.1.2, can I jailbreak it so that it's untethered because he uses it a lot for business and it wouldn't be good if it went flat/needed reboot on him. HE DOES NOT NEED AN UNLOCK, he uses the carrier sim anyway. I also read somewhere that the jailbreak has something to do with the 'bootrom' of the 3GS, could someone explain this please? Also, he doesn't want it to erase any data and I know blackra1n doesn't erase but yeah just saying.