I love April Fools' Day. I don't typically play many pranks myself, but I love journeying through the Internet every April 1st to see what various game and media companies are doing to commemorate this special "holiday."
Blizzard Entertainment, producer of World of Warcraft, never fails to disappoint. Each year they issue announcements about upcoming features for their games, some of which are so well-crafted that many players are taken unawares and actually believe them. One year, they announced that a new race for an upcoming expansion was the Wisp, and would feature permanent death (i.e., if you were defeated in battle, your character was permanently dead with no hope of coming back to life). This year, they've announced a couple of new "features" for WoW, as well as a new way to play StarCraft and an app for Diablo that may cause demonic possession and athlete's foot.
Google usually gets in on the fun, too. This year they've announced Gmail Motion, a new way to use Gmail dependent on body movements. Seems the whole full-body experience is all the rage these days when it comes to computing. The mouse and keyboard are getting up there in years, after all. Funny or Die, last year taken over by Justin Bieber, this year pays homage to Rebecca Black, she of that awful, horrible Friday song that's gotten over 70 million hits on YouTube.
It's gonna be a fun day. :)