Calibre not only provides you an eBook management software but a software to manage your digital library. Calibre alongside with PDF and EPUB supports a variety of other formats. Imported documents can be automatically provided with meta-information by Google Books and converted for specific output formats.
Calibre synchronizes its library seamlessly with a variety of eBook reader like Amazon's Kindle, Sony Reader with, the iPad and iPhone / iPod touch + theApp Stanza and more.
With Calibre RSS feeds can be subscribed to and treated as an eBook.