Another example I like http://blogs.law.harvard.edu/philg/2010/08/08/unemployed-21s...
there was a type of employee at the beginning of the Industrial Revolution whose job and livelihood largely vanished in the early twentieth century. This was the horse. The population of working horses actually peaked in England long after the Industrial Revolution, in 1901, when 3.25 million were at work. Though they had been replaced by rail for long-distance haulage and by steam engines for driving machinery, they still plowed fields, hauled wagons and carriages short distances, pulled boats on the canals, toiled in the pits, and carried armies into battle. But the arrival of the internal combustion engine in the late nineteenth century rapidly displaced these workers, so that by 1924 there were fewer than two million. There was always a wage at which all these horses could have remained employed. But that wage was so low that it did not pay for their feed.
The arguments people make against this are that humans aren't horses. Humans can learn and adapt much better. But they can't do that infinitely, and some will reach their limits faster than others.
This has been happening in China too -- recently(late last year) there was news about Foxconn replacing over a million jobs with robots in China. What this means is cheaper products which are also accessible to those who don't work. It narrows the purchasing power gap between those who work and those who don't.
Then why don't we have 80% unemployment? Because we found other jobs for those people, the economy is much, much bigger, life is much, much better and everybody is better of.
And it isn't like that hasn't happened again and again and again through history.
So I ask you, what proof do you have that this time it is really different? As opposed to every other time we thought it was different through history?
This last point is the difference that this new wave of automation has compared to the waves of past. It is unprecedented in human history to be facing a future where human effort can be multiplied by such enormous multiples that the value of labor approaches zero. This coming automation revolution would have to simultaneously grow the economy to greater proportions that automation reduces the cost of labor. I don't believe this will ever be possible, but definitely not in the time period that a properly developed AI and robotic technology could corner the market in labor (once developed, less than a decade). Society is not prepared for what is coming, and it will be disastrous.
Or, assuming you are right and delivery men are unemployed in great numbers which I agree is likely, then (as transportation prices plummet) there will be more jobs for packaging. Imagine that instead of having to collect your kids in day care, go shopping and the go home and cook you can instead preorder your groceries, have your Google Car pick up your kids, spend the time talking with them in the car, go to the shop and pick up your package (which will take 10 minutes at most, since you have likely already been charged when you made the order) and then home to cook, which kids you actually get to talk to and who are now a lot less stressed.
Even then self-driving cars will also create other oppertunities, because there is no reason the car has to stay in the lot until you get home. It might as well drive to the nearby car cleaner (which can be out-of the way since the time is essentially free, although the gas used is not) for a cleaning. That is more business (and it is low skilled) and better, nicer cars.
Until next year a new type of window will come that doesn't have to be washed.
> there will be more jobs for packaging
There won't. Humans are already being optimized-out of packaging by automated, self-adjusting warehouses and package machines.
> you can instead preorder your groceries
Being produced, packed and delivered by machines.
> It might as well drive to the nearby car cleaner
Which has been automated-out of his work years ago because how this job requires any skills cheap machines don't have right now?
Rest of the things you write about are things people will be able to do instead of working.
The point is, computers are not replacing particular jobs and creating new ones (of similar skill levels). They are replacing whole classes of skills humans have with jobs that have significantly higher requirements and significantly less open positions.
But it is a bit presumptuous to believe that all future inventions will destroy jobs. A great example of the reverse is the compiler industry.
As compiler technology / programming languages have become easier and easier... smaller and smaller teams of programmers have been able to get more things done. This hasn't destroyed programmers... it has instead increased the demand of programmers.
Nor has invention of internal combustion engine decreased the demand for cars. Programming today is far from its full potential, just like transportation was 100 years ago. Software is a very young technology and it is just beginning to take over the world, but keep in mind that developing it is a) high-skill job, and b) mostly aimed toward automating other people out of their jobs.