Project Gutenberg, if you don't know, is a webpage collecting
electronic books online. It was founded in 1971 (yes, long
before the Internet as we know it today existed), when Hart
typed the Declaration of Independency on a Xerox mainframe. Hart
can be seen as the inventor of electronic books - 40 years ago.
We're still waiting for ebooks to get into mainstream.
Currently, ebook reading devices are available, but their usage
is not widespread yet. But I'm almost certain that ebooks will
become very important within the next years. Hart had that
opinion 40 years ago. Today, Project Gutenberg has about 36.000
books. Most of them are public domain, because their copyright
expired. There are other similar projects today: Wikisource is a
sister project of Wikipedia and archive.org has a lot of scanned
books, including most of the public domain books digitalized by
Google. Some mission statements for Project Gutenberg from
Michael S. Hart (taken from Wikipedia) I find that sum up things
very well: "Encourage the Cr