First, what do you want it for? If you want to 'downgrade' a new iPhone that shipped with 1.1.2, well, there is nothing that you can do on a downgraded-to-1.1.1 that you can't do on a native 1.1.2 phone. (i.e. downgrading to 1.1.1 won't allow you to unlock your phone.)
First, what do you want it for? If you want to 'downgrade' a new iPhone that shipped with 1.1.2, well, there is nothing that you can do on a downgraded-to-1.1.1 that you can't do on a native 1.1.2 phone. (i.e. downgrading to 1.1.1 won't allow you to unlock your phone.)