I read the book in a single setting about a month ago, and been through it twice more since. Very well written. The movie will have a hard time competing.

In the afterward, the author mentions that at first he was afraid the book would be too boring, and he'd have to engineer a few 'natural' disasters to keep it interesting. As the book unfolded however, he realized that all too often the solution to one problem creates the next problem. This allows the story to flow in a pretty believable manner.