"[U]se the free Stanza desktop application to convert an ePub ebook into AZW (or even PDF), a format that your Kindle can understand. \ Google Books has more than a million public domain (out of copyright) books in the #EPUB format that are completely free. \ Project Gutenberg and FeedBooks are some other useful sites that offers most of their titles in the EPUB format. \ Firefox users can download EPUBReader, a free add-on that lets you read the contents of any ePub book. \ Use Amazon’s Stanza program to convert your document into an ePUB ebook. \ or use the free Calibre program to convert virtually any document format into ePUB in a batch." - Adriano from Bookmarklet