Google has celebrated the life of Douglas Adams on the late sci-fi author's 61st birthday with one of its customary 'Doodles'.
An interactive graphic has temporarily replaced the Google logo on its search page, and is filled with references to Adams' books and ideas.
The doodle features numerous 'easter eggs', including an animated Hitchhikers Guide and an appearance by Marvin, the Paranoid Android.
Adams is best known for the Hitchhikers Guide To The Galaxy, a series of radio shows, novels and eventually video games and movies about a bizarre journey across space and time. He also wrote the Dirk Gently series of detective novels, and the cult video game Starship Titanic.
Adams was born on 11 March 1952, and died in 2001 at 49 in California, from a heart attack.
Alongside his beloved books and games, Adams has long been noted for his imaginative contributions to the world of tech - and the similarity of many modern devices - from iPhones to eBooks - to his Hitchhikers Guide (first published in 1979).
Adams was also the first person in Europe to buy and receive a Macintosh computer - the second being Stephen Fry.
George Ferris and Valentine's Day
On February 14th, 2013, Google celebrated both <a href="http://www.huffingtonpost.com/2013/02/14/george-ferris_n_2685966.html" target="_hplink">Valentine's Day and George Ferris's 154th birthday</a> with this interactive doodle.
On November 7, 2011<a href="http://www.huffingtonpost.com/2011/11/07/marie-curie-google-doodle_n_1079560.html" target="_hplink"> Google celebrated</a> what would have been the 144th birthday of the mother of radioactivity, two-time Nobel Prize winning scientist Marie Curie.
International Women's Day
Google celebrated International Women's Day 2013 with <a href="http://www.google.com/doodles/womens-day-2013" target="_hplink">this doodle by Betsy Bauer</a>.
One of the great and super nerdy Google doodles, this Jul 23, 2009 logo celebrates the annual Comic-Con conference.
<a href="http://www.huffingtonpost.com/2011/06/09/how-to-play-guitar-on-google_n_873895.html" target="_hplink">Google introduced</a> a super cool doodle on June 9, 2011, an interactive electric guitar to honor the 96th birthday of legendary musician and guitar innovator Les Paul. The Google guitar could play 10 notes from users' computer screen.
On February 6th, 2013, Google celebrated archeologist <a href="http://www.huffingtonpost.com/2013/02/06/mary-leakey_n_2630671.html" target="_hplink">Mary Leakey's 100th birthday</a>.
Google celebrated astronomer <a href="http://www.huffingtonpost.com/2013/02/19/nicolaus-copernicus-google-doodle_n_2717419.html" target="_hplink">Copernicus's 540th birthday</a> on February 19th, 2013.
On January 18, 2012, Google joined Wikipedia, Reddit and thousands of other sites for a c<a href="http://www.huffingtonpost.com/2012/01/18/sopa-pipa-google-logo-doodle_n_1212187.html" target="_hplink">ontent blackout in protest of proposed Congressional legislation</a> calling for strict enforcement of U.S. copyright law online. The Stop Online Piracy Act (SOPA) and PROTECT IP Act (PIPA) drew the ire of web users who feared these bills would lead to unchecked web censorship. As a result of the massive protest, key Congressmen who had previously supported the bills reversed their positions; SOPA and PIPA were tabled indefinitely.
The <a href="http://www.google.com/logos/logos98-3.html" target="_hplink">first-ever Google doodle</a> was a simple stick figure behind the second "O" in the logo on Aug. 30, 1998. It represented the founders' recent trip to the Burning Man festival.
Sir Isaac Newton
On March 1, 2010 Google honored the 366th birthday of Sir Isaac Newton with its first-ever animated Google Doodle.
<a href="http://www.huffingtonpost.com/2011/10/31/happy-halloween-google-doodle-pumpkins-video_n_1066989.html" target="_hplink">Google wished</a> users "Happy Halloween" Oct. 31 with a new video doodle that shows a team of crafty Googlers carving six enormous pumpkins to spell out the search engine's name.
<a href="http://www.huffingtonpost.com/2011/09/24/muppets-google-doodle-jim-henson_n_979011.html#s371509&title=Jim_Henson_Google" target="_hplink">On Sept. 24, 2011</a> Google's homepage featured a medley of Muppets, honoring the 75th anniversary of the birthday of late Muppets creator Jim Henson. On the interactive logo users could play "puppeteer" by clicking on the colored circles beneath each of the characters, which opened their mouths, and the Muppets followed the cursor with their eyes when you moved your mouse. One of the characters would throw his glasses into the air, and another actually ate a fellow Muppet.
Google honored <a href="http://www.huffingtonpost.com/2013/01/31/jackie-robinson-google-doodle_n_2589665.html" target="_hplink">baseball legend and civil rights activist Jackie Robinson</a> on his 94th birthday on January 31st, 2013.
Happy Holidays 2011
On Christmas Eve 2011, Google posted a holiday-themed doodle that serenaded visitors with "Jingle Bells".
This Google Doodle went live for some on September 4, paying tribute to Queen frontman Freddie Mercury, who would have celebrated his 65th birthday on September 5.
Google's Oct. 12, 2011 doodle illustration featured a brightly colored interactive tribute to artist Arthur "Art" Clokey, who would have turned 90 on October 12. In place of the company's logo, red, yellow, blue and green balls of clay bounced around and sprang to life at the click of a mouse, in an homage to Gumby, Clokey's best known animated character.
In honor of Pacman's 30th anniversary on May 21, 2010, <a href="http://www.huffingtonpost.com/2010/05/25/google-pacman-doodle-devo_n_588605.html" target="_hplink">Google gave its logo</a> over to the iconic arcade game with the first ever playable Google Doodle. The logo had 255 levels.
<a href="http://www.huffingtonpost.com/2011/05/11/martha-graham-dance-google-logo_n_860402.html" target="_hplink">Google celebrated</a> the 117th birthday of dancer Martha Graham -- known throughout the 20th Century as a pioneer of contemporary dance -- with an amazing animated doodle on July 11, 2011.
<a href="http://www.huffingtonpost.com/2011/05/09/roger-hargreaves-google-logo-little-men-little-miss_n_859264.html#s276080&title=Little_Miss_Sunshine" target="_hplink">Google celebrated</a> what would have been the 76th birthday of Roger Hargreaves, creator of the "Little Men" and "Little Miss" series, on May 9, 2011. Google featured a colorful cycle of doodles depicting several of Hargreaves' animated characters, including Little Miss Sunshine, Mr. Tickle and Mr. Messy.
Google's 13th Anniversary
Google celebrated its 13th anniversary on September 27, 2011, with a simple, birthday-themed doodle and a scrapbook-style doodle featuring the company's logo letters dressed in a birthday hats and sitting around presents and a birthday cake. <a href="http://www.huffingtonpost.com/2011/09/27/googles-13th-birthday-doodle-logo_n_982798.html" target="_hplink">Check out more photos here</a>.
On Mother's Day May 8th, Google tipped its hat to moms everywhere with a spring-themed logo with a purple flower in place of the "L."
Google celebrated the Royal Wedding of Prince William and Catherine Middleton on April 29, 2011 with a Google doodle depicting a festively illustrated panorama of Westminster Abbey, where the royal knot was tied.
On April 22, Earth Day's 41st birthday, Google celebrated the occasion with a colorful animated doodle. Running your mouse over the illustration's playful animal characters brought the scene to life.
On April 16, 2011 <a href="http://www.huffingtonpost.com/2011/04/15/charlie-chaplin-google-doodle-_n_849587.html" target="_hplink">Google celebrated</a> what would have been the 122nd birthday of one of film's greatest stars, Charlie Chaplin, with a black and white video doodle.
On 12 April 1961, Russian cosmonaut Yuri Gagarin became the first human to enter outer space. <a href="http://www.huffingtonpost.com/2011/04/12/google-doodle-yuri-gagarin-first-man-in-space_n_847914.html" target="_hplink">Google's commemorative logo</a> was dedicated to Gagarin's flight into space.
<a href="http://www.huffingtonpost.com/2010/10/08/john-lennon-s-birthday_n_756064.html" target="_hplink">Google celebrated</a> what would have been John Lennon's 70th birthday on On Oct. 9, 2010 with the first-ever Google Doodle video. The video played a hand-drawn animated version of Lennon's song "Imagine."