Technological innovation:
Dave Winer: "Someday I hope to meet someone who's never seen a typewriter."
I've often thought about the fact that my kids will have no clue what a "record player" is. They'll understand the word "record" (but think CD). Actually, maybe they won't even do that -- by the time my kids are old enough to buy music, it's quite possible that nobody will buy physical media anymore at all, for anything. Crazy...