Google is offering free PDF downloads at Google Books, of those books in the public domain. You can then print them out.
You can download titles like Ralph Waldo Emerson’s Essays (see example here), Dante’s Inferno and Carlyle’s Samuel Johnson.
Downloaded books carry a watermark identifying Google as the PDF’s origin. Perhaps a bone to publishers Google is trying to negotiate with, who will only get more nervous with this sort of printing capability.