This series by David Moody is AMAZING!! He also has some other novels out, Hater, Trust, Straight To You, they're all excellent.
floridapossum, you are correct, the movie is terrible!! very slow, characters are weak!! The only good part of the whole 21/2 hours (it seemed) was David Carradine!! wow, I miss him as an actor, he has done some great work, and he was always able to convey creepiness!
If zombies ever did take over the world, I imagine it would be much like this story, Moody is really able to make you feel the quiet and isolation in a dead (or undead) world. Also the progression of the "walkers" seemed a little more realistic than bodies just jumping up and starting to eat people, I really liked how these zombies more or less just crushed their victims with their sheer masses.
If you guys have not read these books, you really should, they're just great!