There used to be hundreds of thousands of people employed making horse carriages, saddles, tack, and buggy whips. There used to be stables in every town and city, each employing lots of people. Everyone forgets what a huge business ice used to be before refrigeration; hundreds of thousands were employed in the harvesting of ice each winter and in the transport, storage and delivery of ice year round.

Maybe all those jobs will be re-created - who knows?

Times change. Nobody gets a guaranteed lifetime job (except maybe tenured academics, and even then only if their institution and program continues to exist).

I am not the first one to think that perhaps if energy will from here on out become increasingly expensive, then the long-term trend of substitution of energy-powered mechanization for human labor might unwind, and the demand for human labor increase. There could be a demand for plenty of workers in the future for jobs that don't even exist now. Unfortunately, most of these are not likely to be well-paying jobs.

And we still haven't addressed our seeming need to grow. Because if we calculate the minimum necessary to maintain foodstocks, infrastructure, etc., and implement a suitable plan but we keep growing, then we are at this point again in 10 to 30 years, and left with no more efficiencies to find, no more slack to take up, no more fat to trim from the system.

Oh! YES! YES! YES!

This is the point which is ABSOLUTELY, CONSTANTLY OVERLOOKED.
Even if we could get out of the current predicament this would be of no use and even DETRIMENTAL if we don't find a cure for the general problem of decreasing marginal returns (and population growth too).
Deep lack of understanding of Tainter's ideas (or plain ignorance).

While the majority of people on this blog agree with "wasteful" energy usage, those wastes supply people with hundred of millions of jobs worldwide. Those jobs to supply the world with iPods, sports cars, gaming LANs, and plastic everything.

Jobs don't matter. What matters is basic needs, and long term survival of the species. What's the point in making a lot of people fat, dumb and stupid just for the sake of having a lot of people?

How many different programming languages, cereals, shoe brands, and cosmetics do we need as a society?

And who makes the call? And what happens to the suppliers and consumers of the obviated options?

I make the call. Or I can tell you how to make the call. It's called "Net Creativity", or "Good and Evil" or "For the Children". Nature decides which species survive based upon their Net usefulness to the future after subtracting the resources they consume. Good and Evil is determined by what benefits the most people FOR THE LONGEST TIME. Our Children will need resources to survive. They don't need 6.5 billion people in order to preserve the future capabilities of our species.
Whether we figure out how to live cooperatively and rationally as a species will be determined by our forethought and planning. It is already too late to preserve the 6.5 billion numbers that we have spawned. Nature will see to that. However, we have to decide how to preserve as many as we need to ensure genetic diversity and adaptability for whatever disasters may come, or to be able to prevent such disasters to our planet. In other words, we can't throw away all of our knowledge and technology and live in caves, but we need to live in the caves that are available, and minimize our impact so that we have a possible future to save for at least some of the species.
Cooperation, trumps competition. Wisdom trumps blind faith, conservation trumps consumption, Scientific caution trumps corporate profits, needs trump wants, and especially; future needs trump present demands.

Since it's poppycock, can you explain to me the operational difference, other than vocation, between a serf and a person with no property rights and no habeus corpus? 'Cause Americans happily submitted both those things in the last year or so. Who needs rights, we've got American Idol!
Regardless of whether it has happened already or not, you're both overlooking the third population group, the new middle class: feudal soldiers personally loyal to those few thousand lords, whose job will be to encourage folk to submit to serfdom. Feudalism will be making a comeback, not least because it relieves the masses from the terrifying burden of thinking.
IMO, anyone looking to learn a useful post peak skill should consider learning to make black powder and muzzleloaders.

"Let us wrestle with the ineffable and see if we may not, in fact, eff it after all."
-Dirk Gently, character of the late great Douglas Adams.

I've been trying to make that very point for quite some time now.