Nathan Rinne has self-archived "Teaching with Google Books: Research, Copyright, and Data Mining" in E-LIS.
Here's an excerpt:
Google's Google Books site is a rich resource that is probably underutilized by most educators. It has all kinds of potential for a) getting students into the research process in a way that they will enjoy (for example, they can see how a famous quote has been used/quoted, find out which books cite the journal article they are interested in, or check to see if a specific book covers a topic that they want to explore, etc.); b) teaching them about the deeper civic purpose and the evolving state of copyright law; and, c) exploring, with the help of Google Book's Ngram viewer, the promise and ethics surrounding the issue of data-mining and "non-consumptive" research, or research that is accomplished by "mining" books for data, as opposed to reading them.