My iPhone 3G status is as below:
Official SIM not available
my requirement is:
What is the latest version of OS I can upgrade to on my iphone 3G? Any adverse side effects of upgrade (specifically battery)?
I need unlocking (phone useless for me without that). Need guidance on how to jailbreak and unlock without official SIM.
Thanks in advance.
you are really lucky, you have an unlockable baseband. You can update up to 4.2.1, but very important you must update using a custom firmware (done with snowbreeze )so you will not update the baseband.If you update normally by itunes will not be able to unlock (at least not without side effects) .If you update using a custom firmware and then unlock will be no problems.Let me know if it worked, if not if you want can do it online for you, just send me a PM