openDesktop.org :
calibre is a e-book library management application. It is free, open source and cross-platform in design and works on Linux, OSX and Windows. calibre is meant to be a complete e-library solution and thus includes, library management, format conversion, news feeds to ebook conversion as well as e-book reader sync features.
A video demonstration of some features is available at http://calibre.kovidgoyal.net/downloads/videos
