9781840237429, titled "Don't Panic: Douglas Adams & the Hitchhiker's Guide to the Galaxy" | Reissue edition (Titan Books, October 1, 2003), cover price $21.95 | About this edition: Adds extra information to the Hitchhiker trilogy, including previously unpublished radio show excerpts and a profile of Douglas Adams.

9781840235012 | Titan Books, May 1, 2004, cover price $10.95

9781848564961 | 5 rev upd edition (Titan Books, September 15, 2009), cover price $14.95

9781403945778 | Palgrave Macmillan, May 2, 2005, cover price $69.99 | About this edition: Explores the science behind the writing of Douglas Adams' classic novel, and identifies the scientific debates that inspired such plot devices as the Babel Fish, space tourism, sentient computers, and the significance of the number forty-two.

9780230008908 | Palgrave Macmillan, August 8, 2006, cover price $14.95

9780230008908 | Palgrave Macmillan, August 8, 2006, cover price $14.95

9781403997265 | Reprint edition (Palgrave Macmillan, August 6, 2006), cover price $14.95 | About this edition: Explores the science behind the writing of Douglas Adams' classic novel, and identifies the scientific debates that inspired such plot devices as the Babel Fish, space tourism, sentient computers, and the significance of the number forty-two.

9781932100563 | Benbella Books, April 28, 2005, cover price $15.95 | About this edition: A selection of essays dealing with every aspect of one of the most beloved science fiction series of all time contains work from some of the genre's greats, including Cory Doctorow, Stephen Baxter, and Lawrence Watt-Evans, and covers topics as varied as Vogon poetry to the idea of the Internet becoming a real-life Guide.