The new iOS 4.0.1/4.1 beta update can be jailbroken, but it uses a slightly different method. iH8sn0w updated sn0wbreeze to 1.8 beta to support 4.1 beta. I will not be doing a guide on how to do the MC model devices any time soon though. Download 4.0/4.0.1 firmware update here Download redsn0w v0.9.5b5-5 here: Windows Mac OSX (x86) To get the 4.1 beta, you have to become an Apple developer and download it off their site, or Google it. Instructions: 1a. If you are not jailbroken, simply update to iOS 4.0.1/4.1 beta on iTunes 9.2. 1b. If you are jailbroken, safely update to iOS 4.0.1/4.1 beta using this guide. 2. Download redsn0w 0.9.5b5-5, and the iOS 4.0 update. Yes, the 4.0 update, not the 4.0.1/4.1b update. 3. Start redsn0w and point to the iOS 4.0 update, not the iOS 4.0.1/4.1b update. 4. Click Install Cydia, and if you want, click Enable Multitasking, Homescreen Wallpapers, and Battery Percentage, and then click next. 5. Make sure your device is off and plugged in, and hit next. You will be prompted to enter DFU mode, so quickly follow the instructions presented to you as soon as you click next. 6. After that, all you do is let redsn0w do it's job. Congrats, you have jailbroken iOS 4.0.1/4.1 beta! Now, restore from a backup, sync all your data back, and grab some Cydia apps! If you wish to unlock your iPhone 3G follow this guide.