I have three iPhones, the 2G and the 3G S are on 3.0. The 3G phone was on 3.0 as well but I was having trouble running one app so I downgraded to 2.2.1.
I used pwnage 2.5 to downgrade 3G phone. It was easy, it simply created the custom firmware and I restored the phone using that firmware.
I used pwnage 2.5 to downgrade 3G phone. It was easy, it simply created the custom firmware and I restored the phone using that firmware.