Jailbreak iPhone/iPad/iPod and Cydia working on iOS 4.2/iOS 4.2.1 by Msft_guy's method

As most of you know, Cydia is broken and not running on the new Apple's iOS 4.2 update but today iPhone hacker Johnny Franks could make Cydia working on jailbroken iOS devices running iOS 4.2.

NOTE: Your device must be already jailbroken on iOS 4.2 / 4.2.1 GM, you can check Jailbreak iOS4.2 iPhone/iPad/iPod  and 4.2.1 GM Jailbreak
for full step by step guides to jailbreak iOS devices running iOS 4.2/4.2.1 GM

The  new version of Cydia is not out yet but it's ready, so you can use Msft_guy's method to get Cydia working on iOS 4.2 or iOS 4.2.1.

STEP 1: Now type the following command in Terminal app on Mac OS X:

apt-get install bsdiff
STEP 2: Download Cydia.patch file for iOS 4.2.1 from here and copy it to /Applications/Cydia.app/Cydia_ by SSH’ing into your iOS device. [NOTE: You must have SSH enabled on your device]
cd /Applications/Cydia.app/

cp Cydia_ Cydia.bak

bspatch Cydia.bak Cydia_ Cydia.patch

chmod +x+s /Applications/Cydia.app/Cydia_
STEP 3: Finally, reboot your device and enjoy Cydia.

Now you can enjoy untethered jailbroken iOS 4.2.1 device. Get a look at the screenshot above showing iPod touch 4G running iOS 4.2.1 with Cydia working. We'll be happy to hear any question by commenting in the section below.