Per the World Public Library website: "July 4th to August 4th Download Your Selections From 500,000+ eBooks for Free."
According to their site: "Hosted in World Public Library's multi-terabyte server network is the world's largest digital archive of PDF ebooks and edocuments. Our collection hosts more than 500,000+ PDF ebooks and edocuments. As a member you will have complete access to the entire collection. Our collection is constantly growing and our projection is to reach 600,000 by fall of 2008"
Here is a link to their Facts, Questions and Answers page. According to their price sheet, it is $8.95 per year to become a member, or $2/year per FTE institutional rate (for public librarie, priced per number of cardholders - which could possibly be adjusted).
I downloaded the Northwind Trilogy by David Drake and Bedlam Boyz by Ellen Guon to check it out. It downloaded quickly and I was able to save it to my hard-drive to read. I did go to the public access page to do a search and got an error message, but I could browse collections and download from home page without any problems. And I just did a search using the member search on the home page and it worked for me (but I couldn't download), although I couldn't really find anything I was looking for .
Another thing of note is that on the Baen Books site, they have a free library also of a selection of their books you can download in several different formats for free. Both Ellen Guon and David Drake have free downloads of several of their books as well as many other authors. I downloaded Sunrise Alley by Catherine Asaro in a very nice html format.
And of course, a search for free ebooks through Google turns up several more sites that I didn't check out. You can though!
So go "check it out"!