Here’s another interesting Cydia tweak! Firmware Changer can change your iPhone to iOS 4.1 (or any other one) without updating. Basically, it will not let you update to 4.1, but it will fake to be on 4.1 (or any other version you want to pretend to be on).
Why would you want change your firmware version? You can use it so that whenever your connect your device to your computer, iTunes will not show this annoying message asking you to update to the latest firmware…
Additionally, some apps won’t be installed unless you’re on iOS 4.1, so using this tweak will allow you to install iOS 4.1 only apps (although your mileage may vary).
Firmware Changer is available for free in Cydia via ModMyi repository. Of course you will need a jailbroken iPhone to enjoy this app. You can use our guide posted here to jailbreak your iPhone using Limera1n or GreenPois0n.