I am one of the engineers who built the Google Books NGram Viewer. +Yuan K Shen and I (mostly him) also did the underlying corpus generation and analysis during his internship with Google. It was a great pleasure to work with Erez & JB on their research and now they have given an excellent (and amusing) TED talk on the work.

http://www.ted.com/talks/what_we_learned_from_5_million_books.html

(I am also happy to answer questions or otherwise discuss the data, viewer, tools and research here on Plus)