Merely an hour ago Pod2g released Absinthe 2.0 jailbreak tool for iOS 5.1.1 untethered jailbreak. If you have an A4 based or older device that has previously been jailbroken on iOS 5.1.1, you can download the Rocky Racoon 5.1.1 package to convert jailbreak from tethered to untethered.
iOS 5.1.1 untethered jailbreak is compatible with New iPad, iPad 2, original iPad, iPhone 3GS, iPhone 4, iPhone 4S, iPod touch 3G, iPod touch 4G and Apple TV 2G. Out of these devices, the newer A5 or A5X based ones such as iPhone 4S, iPad 2 and New iPad are the ones that cannot be jailbroken tethered at any point on any firmware. The other ones such as original iPad, iPhone 3GS, iPhone 4, iPod touch 3G, iPod touch 4G and Apple TV 2G can be jailbroken tethered, and for precisely these devices an iOS 5.1.1 tethered jailbreak was released.
So what to do now if you have the aforementioned A4 or older devices jailbroken tethered on iOS 5.1.1. You can either download Absinthe 2.0 manually and do the whole procedure or you can take a much viable and smarter shortcut. The Chronic Dev Team has released a package in Cydia called Rocky Racoon 5.1.1. Just download this package and convert your iOS 5.1.1 tethered jailbreak in to an untethered one in just a matter of seconds.
Though remember the fact that you can not delete this package from your device ever, because the iOS 5.1.1 untethered jailbreak for your device depends upon this particular package. Just launch Cydia store on your device, search for Rocky Racoon 5.1.1, download and install this package. After an automated reboot, your iPhone, iPad or iPod touch will successfully be jailbroken untethered on iOS 5.1.1.