my own opinion is that one way to look out over the 21st century from 2004 is to look out over the 19th century from 1804. At that time Lewis and Clark were getting ready to go west. What were the inventions that most shaped the 19th century. My vote would be for the steam locomotive. In the east the canal system was begun in virginia pennsylvania and new york in the the 1820s. That technology was over 4000 years old. 10-20 years later during the 1830's40's the railroads were built in the following similar paths and the canals. The railroads obsoleted the canals. The technological leap was was far greater than anything seen in recent times. That leap would be about on the scale the author of this story is talking about. a leap on a similiar scale might be the space elevator. http://science.nasa.gov/headlines/y2000/ast07sep_1.htm
change may come too in the political system during the 21st century on a scale as that wrought by the louisiana purchase, mexican war, gadson purchase, civil war, alaska purchase
I still want my flying car!
WHERE are the flying cars!!!
Invention itself is kind of interesting. Untold numbers of inventions have been invented at the same time in different places of the globe.
Get all the dims upstair, and then sever the connections.
Don't forget the telegraph...
I agree with you on the 19th Century for the last singularity, but I'd vote for the invention of the telegraph in the 1840s as the tipping technology. Communication instantly went from the speed of a horse and rider to that of light.
Think about repeating firearms as well.