iPhone dev team member ih8sn0w today released Sn0wbreeze 2.2 an untethered jailbreak tool that supports iOS 4.2.1 firmware. Sn0wbreeze 2.2 will work on iPhone 4, 3GS, 3G, iPod Touch, iPad devices, and it is the Windows alternative for PwnageTool 4.2. Just like the PwnageTool 4.2, Sn0wbreeze 2.2 uses the exploit found by the Chronic dev team that they used in developing GreenPois0n RC5.
The specialty of Sn0wbreeze 2.2 is that with it. We can create custom iOS 4.2.1 IPSW files and jailbreak all idevices without updating the baseband. So later we can unlock the corresponding iPhone model using Ultrasn0w 1.2. Sn0wbreeze 2.2 provides various options to customize the IPSW file output.
Download Sn0wbreeze 2.2
You can download Sn0wbreeze 2.2 from direct link here. Note that you may need. NET Framework 3.5 to run Sn0wbreeze if you are using an old Windows version.
Update: Sn0wbreeze 2.1.1 download available. This update fixes the iBooks issue and adds some enhancements.
Update: Snowbreeze 2.3 to jailbreak iOS 4.3 is now available for download.