If you have upgraded your iPhone (3G, 2G) firmware to 3.1 then you might have lost your Ultrasn0w lock forever (Dev-Team). Fortunately there is way to revert back / downgrade your iPhone firmware 3.1 to firmware 3.0.1 if you have iPhone 3G or iPhone 2G. The procedure below might not work on iPhone 3GS. After you might have downgraded your iPhone firmware to 3.0.1, you may jailbreak it by using the iPhone OS 3.0.1 jailbreak...

In just a couple of minutes, Apple is about to release the new iPhone firmware 3.0 for all iPhone and iPod Touchdevices but the interesting part is that the iPhone Dev Team has already managed to jailbreak and unlock the new firmware.