It is one of the things I like best about all the books. Like a good Disney animated feature there are layers and layers of texture. Exceeding subtle hints, throwaway lines with double meaning. I tend to notice them while I am reading, but sitting here now, cannot think of another good one. Next time I read one, I will take notes. I think FPW is far more clever than most give him credit for.
As a second note, I see that Michael Mann is not resting on the laurels he received from The Keep, and totally f**ked up Blackhat. Like The Keep it should have been hard to make a bad movie given the plot, but he did it. Way to go.