Ships are very energy efficient, shipping will last longer then any other kind of freight.

And we might build a flotilla of very large and very fast nuclear powered container ships to tie togeather the worlds rail networks as a replacement for airfreight.

Besides shipping, there are other business that are either inherently global, or so cheap to deal with on a global basis that I think it will remain.

Medical research, for example, is naturally global because deseases are global.  (Even without cheap oil, enough people will move around to transmit diseases from one community to another, and some diseases can be transmitted long distances by non-human vectors.)

Anything that can be represented by data (music, video, money) can remain a global business, even when it is too expensive to move stuff.

I look at the nineteenth century as a possible model.  Capital was quite globalized; natural resources and labor were somewhat mobile.  Energy intensity was much higher than in the eighteenth century, with things like steam ships, railroads, but we'll probably be able to maintain that level of energy intensity for a long, long time post peak.  Combine that with existing infrastructure (we don't need to reinvent a nineteenth century-style telegraph network because we already have fiber optic cable strung across the world) and the opportunity to remain globalized is high.

I look forward to increased localization, but there's lots of good stuff that comes from globalization as well.

None of which is to say that I think businesses flying people all over the world is a good use of fuel.

As others have pointed out, ships are energy efficient, as well I suspect that video conferencing will become a more commonly used technology.  Some people say that sometimes you need to see the other person's face, and you can.  You'll just have to forgo the handshake, but since a handshake no longer means anything in today's society packed with lies, I think we can live without it.

Regarding my thoughts on if one should leave a job which requires air travel, I think not.  However, it would be in one's own best interests to consider the future, and how much security they have in their position if the "necessary" air travel is no longer possible.  It doesn't make sense in a possible era with a recession or maybe depression on the way to take a job where one would be one of the first to go as a cost saving measure.