[GreenMonkey]

Will throw out another one - C.S. Friedman's Coldfire trilogy. Technically you could kind of call it sci-fi - since it's set far in the future where humans settled on a world where the world reacts and "evolves" based on the thoughts of people, conscious and subconscious.

Since demons and ghosts and everything else scary come out at night (influence of the dark fae) humanity tends to live grouped together in scattered urban centers. Technology is mostly limited to simple machines people can understand (because otherwise their unconscious fears cause them to sabotage themselves...pistols tend to blow up...etc). Magic workings can reinforce the technology's stability but it's still a dubious undertaking.

A favorite of mine.