Typically, speed reading courses aim to get you to speeds over about 200 words per minute. I read a book on speed reading some time ago, and it boiled down essentially on concentrating harder on the main points. I don't think I profited much from reading it. With the technique advertised by Spritz you can make it beyond 600 words per minute by delivering the words in high frequency to locations that help you avoid eye movements. Some news sources have pointed out that this means you can read a novel in about 90 minutes. This is spectacular of course.
A perl command line tool is available at github. For google chrome, there's the jetzt plugin, which works really well and looks fabulous. Installation is straightforward. The word frequency is by default at 400 words per minute.
I like the chrome extension. However, if you use the chrome extension, there's a downside: chrome doesn't open all filetypes, and it is not even consistent - sometimes txt files get opened, sometimes they are downloaded. You can (I did) read books using this extension by converting them to text (e.g. pdftotext), and loading them into the browser. With calibre you can also directly convert to html (ebook-convert input.pdf output.html).
From text you can to html, just by slapping html tags around it, but for readability it's better to trust tools such as txt2html. For e-books in epub format you can use epubtohtml to convert them to html.
Please also see my post on language learning to get more ideas of the possibilities.
Enjoy. Please leave a comment below for questions and suggestions.