Although, iOS 4.3.2 and iOS 4.2.7 update is not users who have jailbroken or unlocked devices but it is recommended by MuscleNerd for jailbreakers to save SHSH blobs for iOS 4.3.1.
How to Save SHSH Blobs for iOS 4.3.1
Download TinyUmbrella for Windows/Mac
Connect your iDevice to your Computer with USB and run TinyUmbrella
Under Connected Devices option in left panel select your device and in right panel click Save SHSH button
SHSH of your iDevice will be saved to Cydia server and to your computer as well.