Within minutes of my sending out a black walnut-cracking SOS, Lindsay from Asheville had texted me the following: "For the black walnuts: I use tongs and a hammer on a stump. Tell me if you decide to do this and I will ask [my Brooklyn boyfriend] to deliver a stump from the back yard."
I should also note that I only knew about the challenge of black-walnut shells (one of the hardest known organic substances!) due to a book Lindsay gave me, the endlessly fascinating Smokehouse Ham, Spoon Bread & Scuppernong Wine: The Folklore and Art of Southern Appalachian Cooking. I highly recommend it!
(Am also curious to hit up my Arkansas kin-folk on the subject of black walnuts, since apparently they're pretty thick in the Ozarks. Not that my particular branch seems to have gone in much for foraging or cooking; they were too busy being in the Bin.)
Oh, and while they're at it, in addition to the stump, they can bring the tongs! And the manpower! I am, however, soaking the nuts for 2 days in water, per the book's instructions, to soften the shells.
I have Big Plans for these nuts, if we ever do manage to shell them and extract any meat from the pile of shards. Don't look now, but it involves brittle...