I have no familiarity with Infocom or Hitchhiker's guide to the galaxy, but this guy seems to have found a hard drive from Infocom containing e-mails, design docs, employee phone numbers, sales figures, and two playable builds of the unfinished "Milliways: The Restauraunt at the End of the Universe," the planned sequel to "The Hitchhikers Guide to the Galaxy." You can play one of the builds, extremely partial as it may be, but hey, now I could say I've played a real text adventure.
Credit goes to Mountain Man on the 3DR boards for finding it.