Google April's Fools collection
Actually this is not very hard to do if you own your server.
In Australia, Google introduced a new service called "gDay", which allows people to search for things that are not happened yet.
In China, Google introduced a new search service called "Human search", which all the enquiries are processed by actual human. It will not appear very funny to non- Chinese. This is a reference to Internet culture in China, real identity of characters in Internet memes are usually exposed by netizens who conducted a real search in real life.
In America, Google Announced the launch of Virgle Inc., a jointly owned and operated venture by Google and Virgin Airlines dedicated to the establishment of a human settlement on Mars.