I wrote this to remove all the extra line breaks in books from Gutenberg.org. It works fairly well; about 10 - 20 pages a minute. It is a client-side web app so it depends on the speed of your machine.
http://www.allthingscomp.com/breakerbreaker.html
If you want to run it locally or move it to another site you will also need this file for the statistics aspect to work.
http://www.allthingscomp.com/Concurr...ll-20080319.js
If anyone has suggestions or requests please let me know. Also, if there is already a utility that does the same thing but faster, please let me know about that.