Is there a jailbreak for iOS 4.2

I want to jail break my 3Gs running 4.2.1. Possible?

Solution 1:

There is a howto in redmondpie.com for jailbreaking the iPhone 3GS with iOS 4.2.1, but it appears there is no unlock yet.

http://www.redmondpie.com/jailbreak-ios-4.2.1-iphone-4-3gs-3g-ipad-ipod-touch-with-redsn0w-0.9.6b4-guide/

Solution 2:

YES! I have it currently on my iPhone 4. It's untethered for last-gen devices, but for the iPhone 4 it's a tethered jailbreak, which means that you'll have to connect it to your computer and use the program (redsn0w) to turn on the phone every time the phone gets turned off or looses power.

If you don't turn off your phone a lot, then it's not big issue, though. And because you have a 3GS, you'll be untethered anyway.

The jailbreak is at http://blog.iphone-dev.org which is the iPhone Dev Team, the MOST reputable source for iPhone jailbreaking. These are the actual people who do the work (or compile it from Geohot). DO NOT trust any info from places like BigBoss, RedmondPie, UltraPWN, or anyone else.