Paris in the Twentieth Century sounds like an historical travelogue, doesn't it? But consider when it was written: Jules Verne wrote his "scientific fiction" novel in 1863, setting it a hundred years into his future. At the time, his publisher considered Verne's descriptions of complex underground railway systems, rampant commercialism, and electronic calculators too implausible. The manuscript lived in a safe until his great-grandson had it published in 1996. As a story, it's not one of Verne's better works, but it holds its own as a marvel of prophetic fiction. The book also serves as a brilliant example of what science fiction is : unlike fantasy, which is the stuff of dreams, science fiction is all about possibilities.
For good or ill, the things you read about in science fiction are theoretically achievable futures-- and many of them have already come to pass. Space travel, robots, artificial limbs, genetic engineering, maglev trains, the Internet, geostationary satellites, and videophones all existed in the pages of science fiction novels long before they became reality. (Sometimes, it's where the scientists got the idea.) E. E. "Doc" Smith was writing about airlocks in 1928-- before there were even jet planes, much less spacecraft!
Of course, not everything happens exactly the way an author envisioned it. In William Gibson's Neuromancer, which the Chapters book club will be reading next week, the celphones his characters lug around would never fit in a back pocket. Sometimes it's hard not to giggle at how far off the mark he falls (hindsight is 20/20, after all). Still, the concept is there, and some of his technology makes it hard to believe that he wrote the book over a quarter century ago. (Gibson jokes in the 20th-anniversary edition forward that if he had dissolved the Soviet Union instead of the United States in his future worldview, he'd probably have been burned as a witch.)
For your reading enjoyment this month, I'm sharing a round dozen of titles set in futures past. After the title and author, I've listed the year the work was written, and the year in which it was set. Have a look... and consider where we might be in another hundred years.
Manifold: Time by Stephen Baxter (1999 / 2010) (SF Baxter)
The Martian Chronicles by Ray Bradbury (1958 / 1999) (ReadingList Bradbury)
2001: A Space Odyssey by Arthur C. Clarke (1968 / 2001) (SF Clarke)
Flow My Tears, The Policeman Said (1974 / 1988) (SF Dick)
Visions of Tomorrow: Science Fiction Predictions That Came True by Thomas A. Easton and Judith K. Dial, eds.
(various) (SF Visions)
Neuromancer by William Gibson (1984 / c. 2004) (SF Gibson)
Make Room! Make Room! by Harry Harrison (1966 / 1999) (SF Harrison)
The Door into Summer (1956 / 2000) (SF Heinlein)
Nineteen Eighty-Four by George Orwell (1949 / 1984) (Fiction Orwell)
Millennium Rising by Jane Jensen (1999 / 2005) (SF Jensen)
From the Earth to the Moon by Jules Verne (1867 / first spaceflight (late 1800s)) (SF Verne)
Paris in the Twentieth Century (1863 / 1963) (SF Verne)
Bonus!: I just discovered The Glossary of Science Fiction Ideas and Inventions  today, and thought it quite fitting to mention here. It's a mini-encyclopedia of technologies and devices dreamed up in science fiction (some now in existence, some not), accompanied by the title, author, and year in which they first appeared. Some of the things on this list might surprise you!