"What does a rain cloud wear under its coat?" six year-old Callaghan McLaughlin asked a person six feet away. "Thunderwear!" Last month, the Canadian first-grader set up a joke booth at the end of his driveway and waited for his audience -- friends and their parents -- to amble by. After a local television show interviewed him, Callaghan became a mini Internet celebrity. Yet, five weeks later, he's driven by the simple desire to brighten someone's day. "Even when you are scared or sad, a good joke makes you feel a little bit better," he explains.