The Hitchhiker's Guide to The Universe was a very unique book, and you did a very good portrayal of the characters(even if he doesn't have two heads) :)
Marvin, the depressed robot; Ford Prefect, trying to look inconspicuously human; Arthur Dent, in his bathrobe; Trillian; and Zaphod (who should have two heads...). All on the Heart of Gold spaceship.