There have been many practical jokes pulled on folks in recognition of this day. In 2005, the media reported that NASA had discovered water on Mars, and had actual pictures on the official NASA website. Those who went to the NASA website to check it out, found a picture of a glass of water sitting on a Mars candy bar.
On April Fools Day in 1996, Taco Bell announced that they had purchased the Liberty Bell, and that they would be renaming it the Taco Liberty Bell. Man, people were calling the national parks department, all in an uproar. Later in the Day, the press secretary for the white house announced that they would also be selling the Lincoln Memorial and renaming it the Ford Lincoln Mercury Memorial.
The April 1985 edition of Sports Illustrated reported that there was a new rookie signed up to play for the Mets. This rookie, named Sidd Finch, supposedly trained by Buddhist monks, was said to have a 168 MPH fastball that he delivered with pinpoint accuracy. Mets fans rejoiced until they found out it was an April Fools joke.
Probably the best April Fools joke ever reported was when the BBC news program “Panorama” reported in 1957 that due to a very mild winter and the virtual elimination of the dreaded spaghetti weevil, Swiss farmers were enjoying a bumper spaghetti crop. Many people called in wanting to know how to grow their own spaghetti tree.