Amazon has recently added a neat feature to the pages on certain books. If you go, for example to, Amazon.com: The Search: How Google and Its Rivals Rewrote the Rules of Business and Transformed Our Culture: Books: John Battelle and mouse-over the image of the book it gives you:
- SIPs: Statistically Improbably Phrases
- CAPs: Capitalized Phrases
- and the ability to search inside the book and get a concordance.
They are providing a simple form of text analysis right on the book page. You can click on a SIP and see what other books (for sale on Amazon) have a high frequency of that improbable phrase.