if you connect your i phone to i tunes, you will see a button restore & update.

do not click this button or do not update if your i phone is not officially unlocked, you will end up on locked i phone, i dont know if they have unlocked software to 3.1 all i know is that 3.0.1 only, then click sync. then you can explore for your self, just dont update to 3.1 if you dont have an officially unlocked i phone thanks......