I was searching for Robert Knox's 'An Historical Relation of the Island Ceylon' when I stumbled upon this two great free resources. I was amazed to see how much free content they had & we are so ignorant as not to use them.
By August 2006 there are 19000 free ebooks in Project Gutenberg.
Material is added only after it has received a copyright clearance according to US copyright law.
They simply provide full text view of books according to the copyright law of the viewers country. There is a link where PDF formats of the relevant ebook can be downloaded if they are out of copyright.
Also from yesterday (August 12) they are offering 42 Banned Books