Topic: Module to track books and their reviews for my users? Amazon access??

I'm currently 'spec'ing out an application to allow my users to review books that are topical to their needs. I started 'stealing' the layout that Amazon seems to keep for each book and relate it to author, reviews, vendors, etc.
I've come around to the idea that if I could find and keep the 'key' for each amazon book and use this as a parent record for my users to review, that I'd be far ahead of the game as no one would have to enter all the laborious data such as ISBN numbers.
Has anyone found a way to access the Amazon 'books for sale' database by a key? Has anyone written such a 'book review' application?
I am grateful to hear any ideas and happy to collaborate.
Thank you,