iH8sn0w has released an updated version for Sn0wbreeze (v1.7) which can jailbreak iOS 4 on iPhone 3GS (New Bootrom) and iPod Touch 2G (MC models). If you have an iPod Touch 3G then either you should be on iPhone OS 3.1.2 or you need to have your SHSH blobs saved for iPhone OS 3.1.2 inorder to jailbreak iOS 4 with Sn0wbreeze v1.7.
Remember that Sn0wbreeze v1.7 will jailbreak iPhone 3GS (New Bootrom) iOS 4, iPod Touch 2G (MC models) and iPod Touch 3G and it will be tethered jailbreak. Tethered jailbreak means you have to connect your iPhone / iPod Touch to your PC / Mac to turn it on incase it looses its battery or your iPhone reboots due to any other reason. So if you will jailbreak your iDevice with Sn0wbreeze v1.7, you have to keep a close eye on the battery of your device. The step-by-step procedure to jailbreak iOS 4 with Sn0wbreeze v1.7 is exactly similar to the initial release. You can find jailbreak instructions here. After you are done with the jailbreak process, you can unlock it with Ultrasn0w 0.93.
Download Sn0wbreeze v1.7
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