If you've found yourself even mildly obsessed with style, art or design over the past score, there's a better-than-average chance you've got a Nicholas Callaway book on your coffee table. And it'll soon be a collector's item. The publishing monolith made his fortunes in the pages of ye old paper-based books, but it seems that he'll be paying off future mortgages with something else entirely. In a recent sit-down with Reuters, Callaway confessed to "betting the ranch" on apps, quietly stroking the capacitive touchpanel on his iPad and gazing fondly into the middle distance. For him, this is a "once in a century" revolution, where an entire industry hits a fork and is forced to continu