jailbreak iOS 4.2.1

       Apple Inc. today had been released iOS 4.2.1 GM for iPhone 4, 3GS, 3G, iPad and iPod touches. This build which is currently available to developers only can be jailbroken using the current version 0.9.6b2 of Redsn0w. For those of you who don’t know, Redsn0w 0.9.6b2 is based on Geohot’s Limera1n exploit which can pwn all iOS devices for life.
      Jailbreak of iOS 4.2.1 has been tested on iPhone 4 and can confirm that it works. Though Cydia wont work just yet because Apple has changed some of the private APIs used by Cydia in iOS 4.2.x because of which Cydia crashes when you try to run. The good news is that an iOS 4.2.1 compatible version of Cydia is ready and will go live as soon as iOS 4.2.1 is released to public. Also since you have full root access on the device, you can install jailbreak-apps via SSH for now until the new version of Cydia is live.

Supported devices are:

• iPhone 4, 3GS, 3G
• iPod touch 4G / 3G / 2G