Project Gutenberg rules. I've seen the free ebooks on gutenberg.org for several years now, but I never had anything that was particularly portable AND had a large enough screen to actually take advantage of them.
Enter the OLPC XO computer and its ebook mode. Suddenly, sites like gutenberg.org, manybooks.net, librarianchick.com, and others have taken on a whole new aspect as potential resources.
I just finished reading A Tale of Two Cities, and I've downloaded multiple other documents that include works by Jane Austen, Benjamin Franklin, and Ludwig von Beethoven.
The OLPC foundation plans to make XO computers available to American school systems sometime this year. Many of the free books I see available on these sites are among The Classics that we studied in either grade school or (more likely) high school. I can easily envision that making the XO available to US students, and having them download free ebooks for study, could save schools some money. Then the school systems can focus on obtaining the paper books and classics that aren't yet available for free online.
It's all good. As are these books. :o) The sensory input of holding a paper book might be absent, but the WORDS are paramount (IMO), and those are present and accounted for. Plus, going the ebook route can be a definite space-saver. I don't expect or want tech to supplant printed matter, but it can, and should, supplement it in such a way that promotes both methods of book distribuiton.