Google actually went and scanned every book they could get their hands on - including the libraries of multiple universities - as part of the Google Books project. It could have been a digital library of Alexandria (I also seem to recall that universities had hoped to make their collections available to their students and faculty at the very least.) I believe the Library of Congress was also scanned, so we could in theory make any book in the collection available to anyone in the world over the internet in seconds at almost zero cost.

Copyright law seems to have locked most of the works in these amazing digital libraries up so that they are currently available publicly only via a search function that returns small excerpts (and even that would have been shut down had Google not prevailed in court against the Authors' Guild's claims of copyright infringement.)

At the very least, it would be nice to be able to read all of the scanned books in the Library of Congress that are out of copyright, out of print, and/or not being sold or rented by the author or publisher.