Mark Cuban just won the world basketball championship. Well, actually it was Dirk Nowitsky and the Dallas Mavericks, but the way Cuban celebrated he might as well have been on the court. And who can blaim him? The guy loves basketball, and with the billions he made selling Broadcast.com to Yahoo! just before the bubble burst, he helped build the Mavericks into a national force. These days, Cuban is busy getting his cable channel HDNet off the ground; that is, of course, when he's not cussing out rival teams or making cameos on Entourage.