In gamer circles, the person who coordinates and runs a gaming session. The dorkmaster is responsible for securing the equipment, knowing and teaching the rules of the game, resolving any issues or disputes, and generally keeping the game flowing; like a dungeon master, but not D&D-specific.
Frank was a terrible dorkmaster; he didn't know how to set up the board and we spent half the game watching him look up rules.
One who has honed their specific area of dorkishness to a high art. All dorks within their own sphere of dorkishness (short wave radio, star wars collectibles, etc.) bow to their supreme dork powers.
Man, I thought I was a comic book geek, but that guy has like 5000 comics in his basement - he is the total Dork Master of comicbookdom.