Originally Posted by
CatJo
You will need to unlock it - it's a pretty straightforward process to jailbreak and then unlock, assuming your phone's baseband is supported. This is likely a bit involved to type up here, but searching should yield a plethora of advice - maybe start at iclarified.com and look at their jailbreak guides.
You could always just buy an unlocked iPhone 4S from the Apple store
Yes I could buy a unlocked 4S but my 3Gs was free and I understand that if you unlock it with Jailbreak you lose the ability to update it. Time will tell Thanks for the info.