Create your own epub using Wikipedia. I don't even know where to begin here, but you can create your own one here: http://en.wikipedia.org/w/index.php?title=Special:Book&bookcmd=book_creator&referer=Main+Page
Here is an epub that took me five minutes to create: https://www.dropbox.com/s/qycbpvs561ctunv/Endless%20Doors%20All%20the%20Way%20Down%20copy.epub
What skills and levels of thought are needed to created useful epubs? I think that this is worth doing as a useful exercise in searching, outlining, organizing, and synthesizing. I wonder if Wikipedia has made this tool an open one so that other wikis can adapt and adopt it?