With the release of iOS 4.1.1 or even 4.2 right around the corner, it would be a wise thing to do to save your iPhone iOS 4.1 SHSH blobs either on Cydia, or locally with TinyUmbrella. Saving your SHSH blobs will be helpful if you ever want to downgrade your iPhone to previous firmware version.
Usually, Cydia does this automatically for you, but to be on the safe side, you can always run TinyUmbrella, which is what I just did. Here is how to use TinyUmbrella to save your SHSH blobs…
Step 1: Download TinyUmbrealla from the official site.
Step 2: Launch TinyUmbrella and plug your iPhone in. TinyUmbrella will figure out automatically what iPhone and iOS you’re on.
Step 3: Click “Save My SHSH”.
Step 4: Done! Just like the image above, you should get a message saying your SHSH blobs were successfully saved both locally and on Saurik’s servers.
If you ever accidentally upgrade to a newer iOS, you’ll now be able to downgrade back to iOS 4.1.