Norse Gods, created by virtue of man's need for them and belief in them, continue to exist on modern earth - but with greatly reduced power due to lack of believers. 
 that would be Douglas Adam's The Long Dark Tea-time of the Soul. 
 American Gods seems to have some very simlar characters and plot devices - except A.G. is darker and has fewer laughs. 
 found the modern Gods a bit unconvincing as incarnations of modern idols... technology/fat boy, media etc 
 can't help feel they could be fleshed out a bit more - instead of fatboy for technology/internet feel some sort of swarm entity would work better 
 maybe they just suffer when compared to the mythological figures because I'm using wikipedia to build a picture of those characters - adds to the story for me . 
 overall - suprisingly enjoyable read with interesting plot. 
 only one real character developed, Shadow, and he appears to be more typical of the young adult genre -strong silent type, previously bullied kid, who's hidden talents and significance emerge over the course of the story.