Back Up Blobs From Your Device with iSHSHit
There's a new alternative for backing up your SHSH blobs that allows you to save your own copy in addition to the one on Cydia. iSHSHit is a new tweak that still uses the Cydia On-File service by default, but also gives you the option to email your SHSH blobs to any address you choose. Best of all, it can be run directly from your phone, rather than requiring you to use a program like TinyUmbrella.
It's about as easy to use as possible: all you really need to do is to verify the information that pops up on your screen is correct and tap Save. After it's finished downloading the SHSHs, go to Manage SHSH and tap the version you want to save locally. This takes you to a blank mail message with the blobs already attached. Address it to yourself and/or any other account you want and you're good to go.
Given that future untethered jailbreaks are pretty much all expected to need earlier SHSHs to work, having a quick and easy way to make sure your blobs are backed up is key. This tool gets the job done with no fuss.