The iPhone Dev Team has finally released PwnageTool 4.1. The application uses Geohot’s boot rom exploit to build custom IPSW/firmware files for most of the iTouch devices out there. By creating custom firmwares, users can update their iTouch device to the latest firmware without upgrading their baseband. This will help them in preserving their unlock and update to the latest iOS as well.
As of now, PwnageTool 4.1 supports the iPhone 3G, 3GS (Old as well as new boot roms) running on iOS 4.1 and the iPhone 4 running on iOS4.1 as well. The Apple iPad running on iOS 3.2.2 and Apple TV 2G running iOS 4.1 are supported as well. The iPod Touch 3G and iPod Touch 4G running iOS 4.1 are supported as well.
At the moment, PwnageTool 4.1 is available only for Mac. Users can read more about PwnageTool 4.1 here.