Since the turn of the century, Google has earned a reputation for its April Fool hoaxes:
It start in 2000 with Google MentalPlex
Google announced a new "MentalPlex" search technology that supposedly read the user's mind to determine what the user wanted to search for, thus eliminating the step of actually typing in the search query.
There was nothing notable in 2001 but then...
In 2002 there was PigeonRank
Google reveals the technology behind its PageRank System — PigeonRank. Google touts the benefits of this cost-effective and efficient means of ranking pages and reassures readers that there is no animal cruelty involved in the process. The article makes many humorous references and puns based on computer terminology and how Google PageRank really works.
Another 2 years passed before 2004 and Google Copernicus Center
Fictitious job opportunities for a research center on the moon. Luna/X (a pun to Linux as well as a reference to the Windows XP visual style and Mac OS X) is the name of a new operating system they claimed to have created for working at the research center.
In 2005: Google Gulp
Google Gulp was a fictitious drink. According to the company, this beverage would optimize one's use of the Google search engine by increasing the drinker's intelligence. It was claimed this boost was achieved through real-time analysis of the user's DNA and carefully tailored adjustments to neurotransmitters in the brain (a patented technology termed Auto-Drink). The drink was said to come in "4 great flavors": Glutamate Grape (glutamic acid), Sugar-Free Radical (free radicals), Beta Carroty (beta carotene), and Sero-Tonic Water (serotonin).
2006: Google Romance
Google Romance was announced on the main Google search page with the introduction, "Dating is a search problem. Solve it with Google Romance." It pretends to offer a "Soulmate Search" to send users on a "Contextual Date". A parody of online dating, it amusingly had a link for "those who generally favor the 'throw enough stuff at the wall' approach to online dating" to Post multiple profiles with a bulk upload file, you sleaze in addition to Post your Google Romance profile. Clicking on either of these gave an error page, which explained that it was an April Fool's joke and included links to previous April Fool's Jokes for nostalgia.
2007: Gmail Paper
The day before April 1, Google changed the login page for Gmail to announce a new service called Gmail Paper. The service offered to allow users of Google's free webmail service to add e-mails to a "Paper Archive," which Google would print (on "96% post-consumer organic soybean sputum") and mail via traditional post.