Unfortunately, starting with iOS 5, Apple changed the restore system of our iDevices so that SHSHs become useless for the time being for iPad 2 and iPhone 4S owners. Practically no owner of these 2 iDevices can restore to iOS 5.0.1 even with a saved SHSH, but this limitation is temporary because iH8sn0w announced today that he discovered a method to downgrade even on iPad 2 and iPhone 4S. The SHSHs for these devices are useless now but in the future they will be but if you haven't saved them then save others for iOS 5.1 because soon a jailbreak solution will be available for this version of iOS as well.
A very simple method for saving a SHSH is the iSHSHit application, which starting today is also compatible with the new iOS 5.1 of the Apple company. The application saves the SHSH locally in iDevices and in Cydia and you can send that SHSH to a computer using the Mail application from iOS. For now, SHSHs for iOS 5.1 are not needed, but as soon as the untethered jailbreak solution is released, there is a good chance that iOS 5.1.1 will be released and you will need SHSHs to downgrade and jailbreak without problems.
