Just a FYI on something I have come across - MS Pocket Reader. It is for E-books but with the FREE OverDrive software you can make your own e-books. It could be used as an alternative to PDF.
http://www.microsoft.com/reader/default.asp
See the link on the right side of the page for Overdrive.
http://www.microsoft.com/reader/default.asp
See the link on the right side of the page for Overdrive.