Using this tutorial you will be able to jailbreak iOS 4.2.1 running on iPhone 3G, iPhone 3GS, iPhone 4, iPod Touch 3G, iPod Touch 4G and iPad. Pwnagetool will also preserve baseband version if you need carrier unlock. If you have updated the baseband to version 06.15, you can use this tutorial. This tutorial uses PwnageTool 4.2 for Mac OS X.
We are not developers of jailbreak utilities, so we cannot assure that everything will work just fine. However we tried this tutorial on several devices and succeeded.
We will use iPhone 4 in our jailbreak tutorial. The process is the same for all devices.
Make a folder called "Pwnage" on the desktop. Download a couple of things:
Apple finally released iOS 4.2 for iPhone 3G/3GS/4, iPad, iPod Touch 2G/3G/4G and even Apple TV 2G. Lot's of new features, especially for iPad. Apple calls new firmware 4.2, however the version is actually 4.2.1. Here are the download links: