A book by Douglas Adams. Main characters inclued Ford Prefect, Authur Dent, Marvin the depressed robot, Trillian McMillan, and Zaphod Beeblebrox. Soon to be a movie. The answer to Life the Universr and everything was found to be 42 by Deep Thought. The question is thought to be "What is 6X7?", but unfortunately the computer designed to formulate the question was destroyed by Vogons for an interstellar highway. Also a FAQ game that is supposed to be stupid beyond belief.
From the Hitchhikers Guide to the Galaxy Trilogy that has 6 books.