I just finished reading this book. This is a book I will fully support for the Hugo, assuming one of the other books is not more deserving. It's groundbreaking and well-written, with well-drawn characters you can really care about.
The basic plot is that the Earth gets surrounded by some sort of shell that blocks out all the stars (except the Sun, which it filters to normal levels), and time inside this shell passes much more slowly than in the outside universe, so that in a day inside, thousands of years pass on the outside. Or something like that; I don't remember the exact scale. The book revolves around the main character, Tyler (who later becomes a doctor), starting when he's 12 years old, and his twin friends Jason (a genius) and Diane (who gets involved in religion), who are a year older, and all of their parents (one of whom owns an aerospace company), as they cope with and deal with and try to figure out and fix this situation.
It did not give me the emotional hit that my most favorite books do, though there are some profound emotional statements in it, but it kept me involved mostly as a work of fine science fiction and how some real people deal with it. The first-person POV is the absolute best I've seen in years--of course, it's so hard to do that it's not done incredibly often, so my sample is not so huge, but this is a very fine example.
The end is very satisfying, and it's a self-contained book.
So anyway, having previously just finished Old Man's War, and comparing it to this, I'm definitely voting for Spin unless one of the other nominated books turns out to be better.
