I've searched and I'm still unclear about jailbreaking... I have a Cingular account (AT&T now, but the sim card is Cingular). If I buy an iPhone 1.1.2 OTB, does jailbreaking it allow me to use the iPhone with my current sim card or will it only work with the sim card inside of the iPhone already? If I can use it with any Cingular sim, should I jailbreak the iPhone using my Cingular sim to start out with? Also, will this allow other people to use their Cingula/AT&T sim cards or will only mine work? Thanks in advance.