Hidden away in the Colorado Rockies, a Sicilian resort, or a Utah ski lodge are some of the most exclusive events a billionaire can hope to attend. Attendee lists are so all-star that even the Goldman Sacks chief executive is a 'third-tier guest' and if you have to ask, you're not invited. Between discussions topics like 'can you marry a robot?' quizzes on tech trends and performances by celebrities, deals are made and executives are hired. More and more of these elite getaways are popping up as guests crave time away from the spotlight with few cameras and everything is...