If you've recently updated to firmware 2.1 (click here for undocumented 2.1 features) and lost your jailbroken status, you've most likely heard that the Dev Team has released QuickPwn 2.1 for Windows users! Some of you have already jailbroken your iPhone 3G on 2.1 firmware when QuickPwn and Pwnage Tool for Mac was released.
To follow along, you'll need to
1. Download QuickPwn 2.1 for Windows.
2. Update to 2.1 firmware via iTunes.
3. Run QuickPwn 2.1 and follow the instructions. You'll need to know how to put the iPhone 3G into DFU mode.
4. Enjoy the jailbreak! Let the customization begin again!
If you're interested in jailbreaking your own iPhone 3G from 2.0.1 with WinPwn 2.0, take a look at this jailbreaking how-to.