Repo owner BigBoss has just released a package into Cydia which allows the user to have a semi tethered jailbreak, removing some of the dangers of a tethered jailbreak. This means that if you run out of power, or if the device shuts down for any other reason, your device will be able to reboot with limited functionality. When you reboot semi-tethered, both Safari and Mail will be disabled, along with any other jailbreak apps or tweaks you have installed. Below is a tutorial on how to semi untether your iOS 5 device.
1. Jailbreak your iOS 5 device using Redsn0w’s tethered jailbreak and boot tethered.
2. Navigate to the Sources menu in Cydia, and add the source: “http://thebigboss.org/semitether”.
3. Open the source, and there should be one package titled “SemiTethered”.
4. Install the package and reboot your device.
5. Your device is now in a semi tethered state, and you will have to boot tethered using Redsn0w so use the disabled features.