Unlock software required for iPhone users to be able to change the SIM card already in the key by the operator with the SIM card vendor other. IPhone SU weakness is that when Apple released a new update and the iPhone frameware SU teresebut installed the update, the iPhone will be locked again and definitely need a new Unlock Software that can run another SIM card.
frameware iPhone with iPhone 3.1.3 will upgrade to IOS 4 shall require a new Unlock Software. To update the IOS 4, has emerged ultrasn0w ver. 1.0 to 1 which can unlock IOS mebuka 4 on the iPhone 4. ultrasn0w ver. 1.0 to 1 can unlock his version before including that for the iPhone 2G, iPhone 3G and iPhone 3GS.
source : here
