Using iPhone on AT&T without contract extension?

[audiophile42]

Just a quick question.

I'm already with AT&T. I'm thinking about buying an iPhone. If I go buy one at the Apple Store, and jailbreak & activate it through ZiPhone, I should be good right? I DO NOT want to extend my contract another 2 years. Or would I have to unlock it? I'd prefer not to simply to keep the warranty. I've been researching this, I'm just looking for a definitive answer. Thanks to anyone that can answer me this quick question.

 

[hobo]

From my experience, you'd need to use iNdependence and unlock it.

I have an existing AT&T SIM and I haven't been able to get it to work to make calls on any baseband newer than 04.02.13. iNdependence downgrades the 1.1.3 and 1.1.4 baseband to this in order to use older SIM cards, and I'm thinking they should still work with existing AT&T SIM cards. I've been putting off trying this since 1.1.4 came out.

edit: finished putting it off, I'm on 1.1.4 on my existing AT&T SIM with 04.02.13_G modem firmware! if I can get my custom apps on here, then I'll be all set and happy now...