As a reminder, to save your SHSH blobs, simply connect your iDevice via USB to your computer, launch TinyUmbrella, and click the “Save SHSH” button.
You can download the newest version of TinyUmbrella from here. The software will run on Windows and OS X.
It’s always a wise idea to backup your SHSH blobs in case you need to downgrade your firmware. Cydia will backup your certificates for you, but TinyUmbrella is a good idea for added precaution.