Apple recently released the iPhone 3.0.1 update for iPhone users. This update was released to fix a SMS vulnerability that Charlie Miller and Collin Mulliner discovered in iPhone OS 3.0. If you have a jailbreak or unlock, you will need to follow the below steps to keep it.
How to Jailbreak iPhone 3.0.1
1. After updating to iPhone 3.0.1 download and install iPhone 3.0 firmware.
Download iPhone firmware 3.0 (filename: iPhone1,1_3.0_7A341_Restore.ipsw)
Download iPhone 3G firmware 3.0 (filename: iPhone1,2_3.0_7A341_Restore.ipsw)
Download iPhone 3GS firmware 3.0 (filename: iPhone2,1_3.0_7A341_Restore.ipsw )
2. Download redsn0w.
3. Follow the guide at the Jailbreak iPhone 3.0.1 post. When you select the firmware, choose the 3.0 firmware instead of the 3.0.1 firmware. This is safe and it works!
Update: If your iPhone 3GS is stuck on “Waiting for reboot” unplug your USB cable and plug it back in.
Unlock iPhone 3.0.1
1. Follow the steps above to jailbreak your iPhone.
2. Once your iPhone is jailbroken, open Cydia.
3. Add repo666.ultrasn0w.com to your sources
4. Install ultrasn0w, and reboot!
5. Now your iPhone should be unlocked.