I wanted to post an update here, and mid-stream thank everyone here who has inspired me to get this far and beyond...
Yesterday I sent off the payments that zero out one credit card, and pull the balance on the other down to what it was early last year. In other words, one of my two credit cards is done, hitting the milestone that I set middle of last year.
And even better, on the other card instead of 12.9% interest, I'm paying 7.9% on $4K of it and 0% on the rest (and should be able to pay of "the rest" before it resumes 7.9% next February). My credit rating is climbing, so next I'm going to look at refinancing my current 6.5% car loan to something that'll probably be under 2%.
One thing that has factored heavily for me so far that I don't generally see in the discussion of debt paydown strategies, is that getting a little breathing room on existing credit can open up options to renegotiate or refinance interest rates on the rest of it, and in that way further accelerate the snowballing. In my case it has gotten my monthly credit card interest payments from about $400/mo to $25/mo with only about 40% of the actual credit card debt actually paid off so far.