Want to unlock iPhone 3.0.1? You must first jailbreak, and then install ultrasn0w from Cydia.
1. Jailbreak
2. Add repo666.ultrasn0w.com to your sources
3. Install ultrasn0w
4. Reboot your iPhone
Now your iPhone 3.0.1 firmware should be unlocked! This works for the current iPhone 3.0.1 update on iPhone, iPhone 3G, and iPhone 3GS.
[via QuickPWN]