Hello all, long time reader first time poster here. I have just been sent back to the US from Japan, and only 2 months after having purchased a shiny new iPhone 4 in Japan. I am now trying to get the phone to work in the US, but I have been unable to figure out what to do and some stores I have visited in NYC have also been unable to provide help. The J iPhone is also locked to a provider, which means I need to unlock the phone to use it with a US SIM. Details on my phone are as follows: iPhone 4 Firmware 4.2.1 Baseband 03.10.01 Can anyone tell me if this phone can be downgraded or otherwise jailbroken/unlocked?