1. authors
1.1. Douglas Adams
1.2. Eoin Colfer
1.3. Neil Gaiman
1.4. Glenn Yeffeth
1.5. John Carnell
2. storyworld
2.1. Characters
2.1.1. Arthur Dent
2.1.2. Ford Prefect
2.1.3. Zaphod Beeblebrox
2.1.4. Trillian
2.1.5. Marvin
2.1.6. Eddie
2.1.7. Slartibartfast
2.1.8. Deep Thought
2.1.9. Benjy mouse and Frankie mouse
2.1.10. The Whale and the Bowl of Petunias
2.1.11. MAJIKTHISE AND VROOMFONDEL
2.1.12. The Cops
2.1.13. PROSTETNIC VOGON JELTZ AND THE VOGONS (AND THE DENTRASSI)
2.1.14. LUNKWILL AND FOOK, LOONQUAWL AND PHOUCHG
2.1.15. L. Prosser
2.1.16. Judiciary Pag
2.2. Places
2.2.1. https://en.wikipedia.org/wiki/Places_in_The_Hitchhiker%27s_Guide_to_the_Galaxy
2.3. Minor Characters
2.3.1. https://en.wikipedia.org/wiki/List_of_minor_The_Hitchhiker%27s_Guide_to_the_Galaxy_characters
2.4. Races, Fauna and Flora
2.4.1. https://en.wikipedia.org/wiki/List_of_races_and_species_in_The_Hitchhiker%27s_Guide_to_the_Galaxy
2.5. Technology
2.5.1. https://en.wikipedia.org/wiki/Technology_in_The_Hitchhiker%27s_Guide_to_the_Galaxy
2.5.2. HGTTG
2.5.2.1. http://www.google.com/doodles/douglas-adams-61st-birthday
2.6. phrases
2.6.1. https://en.wikipedia.org/wiki/Phrases_from_The_Hitchhiker%27s_Guide_to_the_Galaxy
2.7. Fictional Books
2.7.1. by Oolon Colluphid
2.7.1.1. Where God Went Wrong - Book I
2.7.1.2. Some More Of God's Great Mistakes - Book II
2.7.1.3. Who Is This God Person Anyway - Book III
2.7.1.4. Well That About Wraps It Up For God - Book IV
2.7.1.5. Origins of the Universe (in Doctor Who)
2.7.1.6. Everything You Ever Wanted To Know About Guilt But Were Too Ashamed To Ask
2.7.1.7. Everything You Never Wanted to Know About Sex But Have Been Forced to Find Out
2.7.2. Prostetnic Vogon Jeltz
2.7.2.1. Vogon Poetry - The Third Worst Peoetry in the Universe
2.7.3. Vogon Poetry Generator
2.7.3.1. http://www.bbc.co.uk/cult/hitchhikers/vogonpoetry/lettergen.shtml
2.8. Food and drink
2.8.1. Pan Galactic Gargle Blaster
2.8.1.1. http://www.webtender.com/db/drink/3471
2.8.1.2. http://io9.gizmodo.com/how-to-make-a-pan-galactic-gargle-blaster-on-earth-1476307064
2.8.2. Zaphod's Bar (Ottawa)
2.8.2.1. http://zaphods.ca/
2.8.3. Life, The Universe and Everything (Beer)
2.8.3.1. http://beaus.ca/beer/life-the-universe-and-everything/
2.8.4. Gin and tonic
3. art
3.1. Tumblr - https://www.tumblr.com/tagged/hitchhiker's-guide-to-the-galaxy
3.2. Fanart.tv - https://fanart.tv/movie/7453/the-hitchhikers-guide-to-the-galaxy/
4. games
4.1. Supersoft text-based adventure game (1982?)
4.1.1. http://www.abandonwaredos.com/retro-games-item.php?idg=1351&idc=30&game=The+Hitchhiker%27s+Guide+to+the+Galaxy+for+Commodore+64
4.1.2. http://www.abandonwaredos.com/abandonware-game.php?abandonware=The+Hitchhiker%27s+Guide+to+the+Galaxy&gid=1351
4.1.3. http://www.abandonwaredos.com/abandonware-game.php?abandonware=The+Hitchhiker%27s+Guide+to+the+Galaxy&gid=1351
4.2. Trivia Challenge DOS
4.2.1. http://www.myabandonware.com/game/the-hitchhiker-s-guide-to-the-galaxy-trivia-challenge-3y2
4.3. Board Game ideas could be used
4.3.1. https://boardgamegeek.com/thread/252832/ideas-hitchhikers-guide-galaxy-game
4.4. "interactive fiction" or text-based adventure game, distributed by Infocom (1984), revived in 2004 on BBC Radio 4 website
4.4.1. The Hitchhiker's Guide to the Galaxy Game - 30th Anniversary Edition
4.4.1.1. http://www.bbc.co.uk/programmes/articles/1g84m0sXpnNCv84GpN2PLZG/the-hitchhikers-guide-to-the-galaxy-game-30th-anniversary-edition
4.5. "The Hitchhiker's Guide to the Galaxy: Vogon Planet Destructor" top-down shooter, by Atatio (2005)
4.6. The Hitchhiker's Guide to the Galaxy: Adventure Game" graphical adventure game, by TKO Software (2005)
4.7. Hothead Games iOs version of the Guide itself (2011)
4.7.1. http://io9.gizmodo.com/5831478/new-app-turns-your-ipad-into-the-hitchhikers-guide-to-the-galaxy
4.8. Starship Titanic
4.8.1. http://www.starshiptitanic.com/
4.9. Bureaucracy
4.9.1. http://ifdb.tads.org/viewgame?id=zjyxds3s57pgis3x
4.10. Unreleased Sequel to Hitchhiker's Guide to the Galaxy
4.10.1. http://waxy.org/2008/04/milliways_infocoms_unreleased_sequel_to_hitchhikers_guide_to_the_galax/
5. stage
5.1. Institute of Contemporary Arts in London (1979)
5.2. Touring show throughout Wales (1980)
5.3. Rainbow Theatre in London (1980)
5.4. Touring Production (2012)
5.4.1. Hitchhiker's Guide To The Galaxy Radio Show Live
5.4.1.1. https://en.wikipedia.org/wiki/The_Hitchhiker%27s_Guide_to_the_Galaxy_(radio_series)#Live_tours
6. Merchandise
6.1. 1980s - towels, t-shirts, Beeblebears, buttons, novelty singles, more
6.2. prop replicas of objects seen on the Vogon ship and homeworld, sets of "action figures", a gun—based on a prop used by Marvin, the Paranoid Android, a crystal cube, shot glasses, a ten-inch version of Marvin, and "yarn doll" versions of various characters. Also, various audio tracks.
6.3. Etsy - https://www.etsy.com/market/hitchhikers_guide
6.4. Collector Cards
6.4.1. http://www.tradingcarddb.com/ViewSet.cfm/sid/78744/1994-Cardz-Hitchhiker's-Guide-to-the-Galaxy
7. events
7.1. Douglas Adams at the 1979 World Science Fiction Convention
7.2. H2G2 con, Hitchercon I, in Glasgow, Scotland (1980)
7.3. Towel Day - May 25th
7.3.1. http://towelday.org/
8. movies
8.1. The Hitchhiker's Guide to the Galaxy (2005)
8.1.1. http://www.orcahome.de/images/stuff/h2g2moviescript_rev3.pdf
9. books
9.1. The Hitchhiker's Guide to the Galaxy (1979)
9.2. The Restaurant at the End of the Universe (1980)
9.3. Life, the Universe and Everything (1982)
9.4. So Long, and Thanks for All the Fish (1984)
9.5. Mostly Harmless (1992)
9.6. And Another Thing (2009) by Eoin Colfer
9.7. Omnibus edition 2 - The Ultimate Hitchhiker's Guide, Complete and Unabridged (1997)
9.8. Short story "Young Zaphod Plays it Safe"
9.9. Douglas Adams's Starship Titanic, by Terry Jones
9.10. Short story "The Private Life of Genghis Khan"
9.11. Audiobooks (mid 80s, 1994, 2005)
9.12. Omnibus edition 1 - The More Than Complete Hitchhiker's Guide, Complete and Unabridged (1987)
10. TV
10.1. The Hitchhiker's Guide to the Galaxy, 6 episodes on BBC2 (1981)
10.2. Adapted segments of several of the books part of the BBC's The Big Read survey and programme (2003)
10.3. The Making of the Hitchhiker's Guide to the Galaxy
10.3.1. Kevin Davies
11. comics
11.1. DC Comics and Byron Preiss Visual Publications
11.1.1. The Hitchhiker's Guide to the Galaxy (1993)
11.1.2. The Restaurant at the End of the Universe (1994)
11.1.3. Life, the Universe and Everything (1996)
11.1.4. Graphic novelization of the three previous (1997)
11.2. authors/artists
11.2.1. Steve Leialoha - Art
11.2.2. John Carnell - Story
12. radio
12.1. 1st Series - 6 episodes, 1978 on BBC Radio 4.
12.2. 2nd Series - 6 episodes, 1980
12.3. 3rd Series, 2004
12.4. 4th Series, 2004
12.5. 5th Series, 2005
12.6. The Hitchhiker's Guide to the Galaxy: The Original Radio Scripts, Douglas Adams and Geoffrey Perkins (1985)
12.7. The Hitchhiker's Guide to the Galaxy Radio Scripts: The Tertiary, Quandary and Quintessential Phases (2005)
12.8. Radio 4 broadcast in front of a live audience (2014)
12.9. LP - The Hitchhiker's Guide to the Galaxy (1979)
12.10. LP - The Hitchhiker's Guide to the Galaxy Part Two: The Restaurant at the End of the Universe (1980)
13. fans
13.1. ZZ9 Plural Z Alpha (http://www.zz9.org/) H2G2 appreciation society
13.2. Wikia http://hitchhikers.wikia.com/wiki/Main_Page
13.3. Fan Fiction https://www.fanfiction.net/book/Hitchhiker-s-Guide-to-the-Galaxy/
13.4. Twitter #HitchhikersGuidetotheGalaxy
13.5. Famous
13.5.1. Elon Musk
13.5.1.1. http://www.businessinsider.com/elon-musk-loved-the-spaceship-from-hitchhikers-guide-to-the-galaxy-2015-6
13.5.1.2. http://io9.gizmodo.com/why-elon-musk-loves-hitchhikers-guide-to-the-galaxys-he-1711846303
13.5.1.3. http://www.wired.com/2015/06/geeks-guide-elon-musk/
13.5.2. Stephen Fry
13.5.3. Sanjeev Baskar (Kumars at #42)
13.5.4. Neil Gaiman
13.5.5. Dany John (Red Dwarf)
13.5.6. Billy Boyd (LOTR)
13.5.7. Monty Python
14. Talent
14.1. Radio
14.1.1. Voice
14.1.1.1. Simon Jones
14.1.1.2. Geoffrey McGivern
14.1.1.3. Mark Wing-Davey
14.1.1.4. Susan Sheridan
14.1.1.5. Stephen Moore
14.1.1.6. Peter Jones
14.1.1.7. William Franflyn
14.1.2. Producer
14.1.2.1. Simon Brett
14.1.2.2. Geoffrey Perkins
14.1.2.3. Dirk Maggs
14.1.2.4. Bruce Hyman
14.1.3. Writer
14.1.3.1. John Lloyd
14.2. TV
14.2.1. Starring
14.2.1.1. Peter Jones
14.2.1.2. Simon Jones
14.2.1.3. David Dixon
14.2.1.4. Mark Wing-Davey
14.2.1.5. Sandra Dickinson
14.2.1.6. David Learner
14.2.1.7. Stephen Moore
14.2.2. Producer
14.2.2.1. Alan JW Bell
14.2.2.2. John Lloyd
14.3. Movie
14.3.1. Starring
14.3.1.1. Martin Freeman
14.3.1.2. Sam Rockwell
14.3.1.3. Mos Def
14.3.1.4. Zooey Deschanel
14.3.1.5. Bill Nighy
14.3.1.6. Anna Chancellor
14.3.1.7. John Malkovich
14.3.1.8. Stephen Fry
14.3.2. Directed
14.3.2.1. Garth Jennings
14.3.3. Produced
14.3.3.1. Gary Barber
14.3.3.2. Roger Birnbaum
14.3.3.3. Jonathan Glickman
14.3.3.4. Nick Goldsmith
14.3.3.5. Jay Roach
15. Lit about...
15.1. Don't Panic: Douglas Adams & The Hitchhiker's Guide to the Galaxy - Neil Gaiman
15.2. Don't Panic: The Official Hitchhikers Guide to the Galaxy Companion - Neil Gaiman
15.3. The Anthology At The End Of The Universe: Leading Science Fiction Authors On Douglas Adams' The Hitchhiker's Guide To The Galaxy - Glenn Yeffeth
15.4. The Science of the Hitchhiker's Guide to the Galaxy - Michael Hanlon
15.5. The Hitchhiker's Guide - MJ Simpson
15.6. The Frood: The Authorised and Very Official History of Douglas Adams & The Hitchhiker's Guide to the Galaxy - Jem Roberts
15.7. Mostly Harmless (HGTTG Fan Zine)
15.7.1. http://zz9.org/mostlyharmless
15.8. Wikipedia HGTTG Portal
15.8.1. https://en.wikipedia.org/wiki/Portal:Hitchhiker%27s
15.9. h2g2
15.9.1. http://www.h2g2.com/
15.10. Life, DNA & H2G2
15.10.1. http://douglasadams.eu/h2g2/#