WorldeBookFair.org has made 2 million pdf eBooks available free to the public from July 4th thru August 4th, 2009. eBook collections come from Project Guttenberg, World Public Library, the Internet Archive's Text Archive and many others. According to their website, the purpose of the World eBook Fair is to:
"Our goal is to provide Free public access for a month to 2 Million eBooks. During the rest of the year you may continue to download your selection of about 500,000 PDF eBooks by joining the World Public Library. Annual membership is only $8.95 per year"
To search the collection and start downloading, visit: WorldeBookFair.org