The World eBook Fair almost slipped past me this year. It started July 4 and ends today.
According to the event website:
Our goal is to provide Free public access for a month to 6.5 Million eBooks (7/4/11 to 8/4/11).
World eBook Fair is sponsored by the World eBook Library, Project Gutenberg, Internet Archive, MyeBook, and Wattpad. Many of these sources offer free ebooks all the time, so even if you miss the World eBook Fair, this page is a good source of finding free ebooks.