from Inside Google Book Search:
Today we launched a new feature for Book Search to help more people access the world’s great public domain works. Whenever you find an out-of-copyright book in our index, you’ll see a “View plain text” link, which lets anyone access the text layer of the book. As Dr. T.V. Raman explains on the main Google blog, this opens the book to adaptive technologies such as screen readers and Braille display, allowing visually impaired users to read these books just as easily as users with sight.
This is an exciting step for us in our mission to organize the world’s information and make it universally accessible and useful. To learn more about Google’s efforts to make books and other digitized content more accessible to everyone, check out Dr. Raman’s full post.