Large carriers such as Delta Air Lines have invested heavily in touch-screen entertainment systems that are built into seat backs. Southwest Airlines and others offer only onboard wireless Internet so passengers can watch movies and television shows using their own tablet computer or smartphone. A few airlines have installed both systems. “Airlines are taking very different approaches because each airline has a different perspective on how they run their business,” said Henry Harteveldt, a travel industry analyst for Atmosphere Research Group. Get the full story at The Seattle Times