I'd be glad to create ePub books as well as the other three formats when I convert a book for uploading here. For now, I'm assuming that Calibre will be the software most available to me -- or maybe the online tool at Feedbooks. I do own a Sony 505 reader, but have not yet applied the update that will enable it to support ePub files. (Long story -- but planned to be done by the end of March 2009.) I don't really want to install Adobe Digital Editions on my computer to read the ePub book, so will need to investigate the various options for display.
Some interesting web places having to do with ePub that I found:
* free, online ePub validator --
http://www.threepress.org/document/epub-validate/
* tutorial on creating ePub books --
https://www6.software.ibm.com/develo...tut/index.html