Yesterday was April Fools' day, and the internet was of course flooded with pranks. Check out what various sites did this and past years at April Fools' Day On The Web.
A couple of the better "direct" pranks I saw highlighted this year were "converting" office equipment to voice commands, eating a jarful of "mayo", and the guy who had his computer bedazzled by his girlfriend (via this post).
Though it's almost certain this heart-attack-inducing prank didn't occur on April Fools', I just had to include it...
Last but not least, Blizzard Entertainment always loves celebrating April Fools' Day, here's a couple of the jokes they did this year: