The Librarian is really worth the money for its convenience if you intend to put many books on the Ebk1150 and use it heavily. Before I gave my Ebk1150 to my father in law I used Librarian heavily and never regretted shelling 15$ for it.
For free there is the ETI software from the original makers of Ebookwise, which has interesting capabilities including batch converting, so I used it once in a while, but the Librarian is so convenient (you have all your imp books in a place, can edit their metadata, sort them, send them to device/card ...)
http://www.ebooktechnologies.com/sup...r_download.htm