Well, sort of. You all remember of course the magical game Relate-a-zon, where you had to navigate Amazon's related items space to get from A DeWalt drill to American Psycho. Adventurers in Relate-aspace soon learned some of the features of the landscape as summarized in the FAQ. Among the observations making the game easier is the existence of hyper jumps - special products that create a relation between otherwise unrelated neighbourhoods in relate-a-space. In the space of books these special gateway links are the subject of an article in New York Times. I found the link via Jon Udell.