Gevey SIM is a hardware based hack that can unlock your iPhone 4 handset running iOS 4.3. The hack involves attaching a thin piece of plastic to your actual SIM card, and inserting both into your iPhone handset.
As opposed to the iPhone Dev-Team‘s ultrasn0w unlock, Gevey SIM is a hardware based hack – meaning you don’t need to jailbreak your iPhone handset to take advantage of it. The “accessory” is essentially a SIM card sized piece of plastic, which users insert into their SIM card tray along with an actual SIM (the SIM you want to use with your iPhone).
Following this, users have to make a few emergency calls and switch over to Airplane Mode a few times (as detailed in the video below). However, once this is done, your iPhone should recognize the new carrier, and you should be good to go.
For more information, check out the video below.
[via Gadgets DNA]