SHSH Blobs & Updates

I've heard that the ATV decides to update itself whenever a new version of the software is out, and therefore it's prudent to save the SHSH blobs.


Apparently this should be done via TinyUmbrella - but I was wondering if there were commands I could do through SSH to extract them? I'm not particularly excited about the prospect of having to do another tethered boot! It took ages to get right last time!