Everyone brings up the Internet. But the internet has not changed people's lives as significantly as railroads, telegraphs, plumbing, electricity, radio, automobiles, central heating, air conditioning, telephone, or television did. I don't mean it hasn't changed it as much as those things combined; I mean each one of those had more impact on daily life than did the internet.
Here's the test I use: look at fictional stories set and written in the time before the technologies. How many of the plot elements have become quaint and obsolete due to the technology?
By my reckoning, for the other technologies you listed, my metric only turns up a few inconveniences here and there which are still present on some level today. In contrast, many stories (even as recently as the early 90s) become laughably quaint given the introduction of a well-organized many-to-many communication/information network.
Knowledge is power, and the internet provides it to people in droves. (cheesy, I know, but fair)
SIAI benefactor and VC Peter Thiel has an excellent article at National Review about the stagnating progress of science and technology, which he attributes to poorly-grounded political opposition, widespread scientific illiteracy, and overspecialized, insular scientific fields. He warns that this stagnation will undermine the growth that past policies have relied on.
Noteworthy excerpts (bold added by me):
In relation to concerns expressed here about evaluating scientific field soundness:
Grave indictors:
HT: MarginalRevolution