Have some fun with Google
Into Google search type these: (one at a time, without quotes) and press search
"askew" or "tilt" will cause the search results to be displayed at a slight angle.
"Atari Breakout" and then clicking Images will start a game of Breakout using the image results as bricks. When one wins it searches something else randomly and plays again.
"Do a barrel roll" or "z or r twice" will cause the search result to rotate 360 degrees when showing. This is often connected with Nintendo's Star Fox games.
"zerg rush" causes a bunch of Google "o"s to attack the result page and eventually destroy it; the user can, however, fight back by clicking on them. After destroying the results, the "o"s then arrange themselves into two capital 'G's, representing the acronym for "good game".
"Bletchley Park" will cause the title of the info card to appear as if it was being deciphered by Google. This is a reference to the fact that Bletchley Park, in Milton Keynes, Buckinghamshire, was the central site of the United Kingdom's Government Code and Cypher School (GC&CS), which during the Second World War regularly penetrated the secret communications of the Axis Powers.
"kerning" will increase the spacing between every letter in the word kerning by 1 pixel whenever it shows up in the search results page. Conversely, searching for "keming" (a common example of unfortunate kerning) will decrease the spacing between letters of the word when it shows up in the search results page.
Searching for any actor's name followed by "bacon number" returns the Six Degrees of Kevin Bacon value.
"Recursion" will result in Google asking if the user meant "Recursion."
"Conway's Game of Life" produces the Life simulation described by Conway.
using Search by voice for "how much wood would a woodchuck chuck if a woodchuck could chuck wood" produces a vocal response of another tongue twister "A woodchuck would chuck as much wood as a woodchuck could chuck if a woodchuck could chuck wood".
"Kwanzaa" returns a green, Kwanzaa background
"Festivus" places a Festivus pole in the left side of the window.
"Santa Claus" or "Christmas decorations" places an animation of a snowy landscape with Santa Claus and his reindeer riding across the top of the search results. On Christmas Eve, a map will appear where Santa is currently located.
"anagram" results in the search engine asking "Did you mean: nag a ram" ("nag a ram" is an anagram of the word "anagram")
"Google in 1998" results in a 1998 Google search screen appearing in place of the current Google search screen. Clicking on the first result will bring the user to the Wayback Machine's version of Google from 1998. However, clicking I'm Feeling Lucky will go to a page showing Google's history in depth.
"Google Pacman" has a playable version of the game appear on the screen.
Jason Isaacs returns "Hello to Jason Isaacs", a reference to the BBC Radio 5 live film review program with Mark Kermode and Simon Mayo.
'who are you' using the voice recognition search causes the voiceover to say 'searching for oneself may take a lifetime. But a good place to start is classic rock.'
"blink html" will make both of the words "blink" and "html" do just that (blink) wherever it shows up in the search results.
"beam me up, Scotty" using voice search produces a vocal response that says "I cannot do it, Captain, I do not have the power." in an impersonation of the character Mr. Scott from Star Trek.
"What does the fox say?" using voice search produces various vocal responses from the song of the same name by Ylvis.
"same sex marriage", "Drag queen" or "gay rights" will cause the navigation bar to turn into rainbow polygons.
Source: Google.
Do you know of any others?