Sn0wbreeze 1.7 to jailbreak iOS 4 Firmware On New Bootrom
What devices Sn0wbreeze 1.7 supports:
iPod Touch 2G
iPod Touch 3G
For iPhone 3GS And iPod Touch 2G (MC), 3G there is something you must now because those devices have a tethered jailbreak. Thus it will require you to re-jailbreak your device each time rebooting or recharging your devices!
After downloaded the tool, you can now follow the tutorial from iH8Sn0w here to jailbreak iPhone 3GS new bootrom on iOS 4 using Sn0wbreeze 1.7
Source : rumahabi.com