Project Gutenberg is a free collection of e-books which everyone can take part in producing. Volunteers are invited to scan or key in pages from books printed prior to 1923, or proofread scanned pages. Anyone can become a volunteer to help preserve history one page at a time. This is an excellent example of how the Internet enables virtual cooperation on an international scale. Distributed Proofreaders coordinate the project and offer a pre-registration online Walk Through demonstrating how it all works.