I already have AT&T with an unlimited data/text plan. If I buy a contract-less iPhone 3G (e.g., eBay or a referral program like TraInn), is there any way to get it working without activation or upgrading my AT&T plan? Would I have to unlock it, or would jailbreaking only worked? I ask this because my mom just bought an iPhone (first gen) off Craigslist, and I set it up by using by jailbreaking/unlocking with QuickPwn and then patching the "Lockdown" plists so that any SIM is pre-activated. Hers works fine now with no problems and we see no negative account additions.