I finally got around to taking the old drain out of the sink and replacing it with the fancy new one that came in the box with my faucets:
So, just so you know, pipes are gross. And there's stuff in pipes that's gross. Ick. Good thing I didn't have my face underneath any pipes when a gob of goo decided to dislodge itself.
Also, I installed an additional towel bar:
Nothing gross about that.