One of the hindrances to a truly seamless Sony Reader experience is the Reader Library software provided by Sony. Though the software is required to purchase ebooks from the Reader Store, it's not the only way to manage content on your device.
calibre is a free and open source ebook management application for Windows, Mac OS X, and Linux operating systems compatible with the complete line of Sony Reader devices. The software offers excellent library management features and robust file conversion options.
One of the major benefits of using calibre is the file conversion utility. While the Sony Reader is not limited to content purchased through the Reader Store, the Reader Library software doesn't give you many options for getting third-party content onto the device. calibre's file conversion can take a huge number of formats—PDF, HTML, RTF, TXT, MOBI, etc.—and output an EPUB file (among other formats) compatible with the Sony Reader.
So what does this mean for your content? Well, it means you can finally make PDF documents readable on the Sony Reader. If you have PDF docs formatted for any size other than the Reader screen, they're usually unreadable on the device, appearing too small at normal size and riddled with awkward line breaks when the font size is increased. With calibre, you can output properly formatted documents with scalable font sizes, ensuring readability on your display.
In one of its best features, calibre allows you to extend the RSS capabilities of your Sony Reader. Currently there are only a limited number of RSS feeds available through the Reader Store. calibre can sync with over 300 newsfeeds and convert them into a nicely formatted ebook—complete with table of contents and other frills—perfectly compatible with your Reader. This feature really extends the content available for the device and makes the Sony Reader a much better contender for the Kindle's throne.
Using calibre means you aren't limited by the content available through the Reader Store. The variety of input formats accepted allows you to take digital books that aren't otherwise available and convert them into compatible ebooks. You can find a huge number of books on torrent sites that can be converted to a format compatible with the Reader. (Of course, you should be sure that whatever you're downloading isn't commercially available—either digitally or in print—before helping yourself to a free copy.)
With calibre, the Sony Reader becomes a much more formidable device. Though there are other ways of getting content onto your Reader through the Reader Library, calibre makes it a lot simpler and is a completely self-contained process, handling both file conversion and library management. Though it can't do the job of purchasing content through the Reader Store, for all your other needs, I strongly recommend using calibre with your Sony Reader. Though it's not perfect yet, with a few tweaks, calibre may be the killer app ebook readers need to win over converts.