The beta version of Google Print is up and running. As everyone has heard by now, Google has been busy digitalizing old books from the NY Public Library and elsewhere. They've done 10,000 books so far, and unless someone stops them in court, there appears to be no end in sight!
Do a keyword search, and Google provides an image of the specific pages of books in which your keyword appears. For example, I searched for the phrase "persevering grace," and got 58 results. Among them, p. 163 of Ryken's The Doctrines of Grace, p. 245 of Boice's The Glory of God's Grace, p. 84 of Oden's The Justification Reader, etc.
It's a fascinating project, but quite controversial. A lot of library-types (my cohort) think Google is evil itself, but I'm not so sure. Many say this project will be a great boon to authors, encouraging sales. Anyway, I would encourage everyone to have a look. I expect to have lots and lots of fun with this.