Do most flat-screen TVs strike you as numbingly similar? That's because under the hood, they are. LCD production is consolidating into an ever smaller number of suppliers. Sony and Samsung compete on store shelves, but they buy their LCDs from the same company — S-LCD, a joint venture. Now Sony is forming a new joint venture with Sharp, another fierce rival. Why? Moore's Law, the overlord of chips, is moving into the TV world. Making an LCD screen requires skill in handling silicon, and billion-dollar investments: Sharp's latest plant costs $3.5 billion, an expense Sony will now subsidize.