As one of the billboard features of Apple iOS 6, Passbook has proven way more useful than we initially anticipated. Amtrak, Fandango, and sports ticketing integration have already made it a welcome addition. But what's really going to make this a killer feature in the future is having all of the world's airlines on board. A few months after launch, Passbook is making some progress towards that ticketing utopia. (gizmodo.com) Mer...