defective yeti's Matthew Baldwin created @textadventurer, a bot that issues Zork commands, and @zork_i, another bot that answers back with what was found. You can follow their exchange on textadventurer.org and read about the project here.
I created the @textadventurer twitterbot to help myself learn the Twitter API. Originally it did nothing but tweet Zork commands, taken from a walkthrough. I was its sole follower.
Oddly, I really enjoyed seeing the text adventurer wander through my twitter feed every hour or so. And when he would tweet, say, "go north," I would find myself curious as to where he was headed. So I eventually created the companion account @zork_i, rebooted @textadventurer, and introduced them to one another. Now they are playing out Zork I in its entirety.