It seems to have been inspired by the LID (Low-Power Interactive Display) on the promising but still unshipped miniature Vulcan FlipStart PC.

ENGADGET: Switched On: Longhorn hardware advances could give PDAs a one-two punch

Unlike similar offerings such as the still-unshipped Clambook (or Motorola's ill-fated Lapdock) the Casebook uses the handset as a trackpad, and the creators say that it won't be device-specific, working instead with a large number of smartphones from Apple, Blackberry, Samsung and others.

ENGADGET