There’s nothing average about ”Average Joe: Hawaii”’s David Daskal. Whether jumping on a couch, tossing a watermelon into a pool, or reciting ”The Greatest American Hero”’s theme-song lyrics, the former mail sorter and star of a Spanish cell-phone ad (vagabond films.com) has stolen the show. ”I used to watch ‘The Real World’ and think, If I’m ever on a show like that, I’m gonna go nuts,” says Carrot Top’s twin. So how will he outdo himself? ”I hear Def Leppard might tour,” he says. ”If I can sing ‘Foolin” with them, my life will be complete.” The scary part? He’s not f-f-f-foolin’.