Here's a list of downloadable books whose authors died fifty years or more ago. In much of the world (Angola, Argentina, Australia, Bahrain, Bangladesh, Barbados, Belarus, Belize, Benin, Bulgaria, Burkina Faso, Burundi, Canada, Chile, China, Cyprus, the Czech Republic, Egypt, El Salvador, Fiji, Ghana, Iceland, Indonesia, Japan, Jordan, (South) Korea, Lebanon, Malawi, Mongolia, Morocco, Nepal, New Zealand, Oman, Pakistan, Panama, the Philippines, Poland, Qatar, St. Vincent and the Grenadines, Saudi Arabia, Singapore, Solomon Islands, South Africa, Syria, Taiwan, Thailand, Togo, Tonga, Trinidad and Tobago, Tunisia, and Ukraine. Bolivia), that puts these books in the public domain, so if you're logging in from one of those countries, download away. Americans and Euros have another 25 years or so before they're legal clickers, though.
The Case Book of Sherlock Holmes, The Great Gatsby, H. Rider Haggard's "Allen and the Ice Gods," 1984, Finngegans Wake, and others.
(via Aaron Swartz)