Since there seem to be two different topics going on here:

1. Future of Travel:

I hardly think we are at the end of travel. I think we are really just entering a golden age of it, really. Until a few decades ago, it was very costly to even provide the equipment to travel great distances. With new technology we have brought that down. Todays planes are so vastly more efficient that they can move people farther than before on less fuel. And I am not so sure about the declining oil as being a catastrophic event - our ability to extract more from those reserves increases daily, and we are finding new ways to find oil. For that matter, fossil based fuels themselves may end up becoming quaint memories as bio and other fuels are developed.

Even given issues such as greenhouse gases and carbon footprints, there is still lots of economy to be realized by larger planes with fewer actual flights.

If anything people are becoming more interested in the outside world. People live in different countries and no longer seem content to stay on one continent. We may loose the novelty factor of foreign countries, we may t the interest is still there.

2. Vacation time:

That is a huge issue in the US. I think it has to do with out fanaticism about numbers. We measure "productivity" as though people are robots that turn on and off. Vacation, as TMOliver said, isn't even about "vacation", it is just rest from work. We have become so slave driven that we in the US anyways think of anything that is not working full out as slacking. That comes from a total disregard for actual work done except in terms of spreadsheet numbers.

I am particularly concerned that we have become so focused on mechanical output that we are sorely missing the point that we can no longer lead in design, ideas, or scientific knowledge. I disagree that we are as sound an economy as other countries - I no longer think that is true and it is, unfortunately, becoming all too clear. The faith from other countries in the Us to lead is diminishing, and with that our ability to lead is rapidly declining - once those other countries realize that they CAN survive without the US, then they wont look to the Us to lead.

Vacation time - time off - is vital to that. Americans live to work. We measure people's quality of life now not by what they do with their life but how many hours they work and what kind of jobs they hold. We somehow now glorify throwing one's life away for the sake of a corporate bottom line. we have essentially sold out our point in living and are now finding it hard to really put any effort into making our lives better.