I've written a few essays here and there. Some for McSweeney's Internet Tendency. Some for other dubious places. Some simply for flat-out, knee-buckling rejection. Followed by pitiful, dragged-to-the-trashcan annihilation. But, honestly, most editors have been good about dispensing thoughtful repudiation, if a little, shall we say, brusque.
I've also done some conceptual illustrations (below not above) for a publication called Kugelmas (which isn't around anymore). I don't honestly know what conceptual illustration is, but there you have it.