At a small but classic library in West St Paul (which is south of St Paul, but on the "west" side of the Mississippi) I came across a book from my childhood: The End of Eternity by Isaac Asimov (1955). It's a time travel book, full of cliches.
Except they weren't cliches then.
At the above Amazon link you'll find "We don't know when or if this item will be back in stock." That's sad. The End of Eternity is not a classic book, but it's a fun book by a man who wrote a lot, and got good at it.
Over at Google Books we learn that the End of Eternity was digitized Mar 25, 2008 at the University of Michigan. We can't read it though. Under current US copyright law it goes into the public domain at about the end of eternity. (You didn't realize copyright was now effectively eternal? Missed that one eh?)
Google gets a lot of flack for their book project. I'm sure they're imperfect, but I think they're fundamentally right.
Update 1/20/10: Ok, so I could have picked a better example. Charlie Stross tells me I should have looked a bit longer (52 reviews, 5 stars). It seemed like such a good example at the time! In my defense the reviews are quite old, and refer to the book as "hard to find" in 2000.
Update 1/20/10b: Charlie wrote this long post today. Google is not his friend. Mea culpa.