Amazon.com has a few new features for some of their books.
The first feature is something called Statistically Improbably Phrases, or SIP. This consists of phrases that are unique, or very unique to this particular book. So if you look up Ender's Game you will discover that "bugger wars, beat the buggers, flash suits and null gravity" are all phrases unique to this book.
Interesting, but Amazon doesn't stop there.
It also gives you some basic stats like Flesch-Kincaid Index (Ender's game is a 5.3), percentage of complex words, and, my personal favorite, words per dollar (Ender's game gives you 16,134 per dollar, which is nothing compared to War and Peace. Good ol' Leo delivers 51,707 words per dollar, though I'm not sure what the conversion to the rubel would do to that.
And finally, you can look at the concordance, which actually uses visual weight to display the 100 most common words in the book. I'm not sure, but I think they leave out words like "the" and "and". Just by glancing at the concordance you can see that "Ender" is the most common, followed by "said".
Anyway, it's an interesting feature, though I'm not sure how directly useful it is. And this isn't on all of the book by any stretch of the imagination. It looks like they have done it only on the more popular books