Members of the iPhone Dev Wiki team have created a restore process which allows some users to regain full use of their iPhone if it has been disabled by Apple's latest firmware update.

The process will take the phone from the latest version 1.1.1 firmware back to the previous 1.0.2 version, allowing users to reactivate the iPhone and regain use of its features.

By reverting to the previous version, however, users will be locked out of the security, stability and feature improvements that the upgrade offers.

The hack will also not help users who cracked their iPhone by changing the firmware of its cellular radio using the 'free SIM unlock' tool. Reverting to the old firmware leaves these users without phone, SMS or Edge functionalities.

Despite its limitations, the reversal allows users to regain control over phones rendered useless after Apple released its update last week.

Apple had warned that the firmware update would cause unlocked iPhones to crash without the possibility for recovery.

There are no known methods of unlocking the 1.1.1 version of the iPhone firmware.