At Lifehacker there is a post about speed reading applications. I created a application for the same purpose for about a year ago.
If you want to try it out, download it from the link below. I find the application useful when I need to read a blog post or article fast.
You need Microsoft .NET 3.5 framework to run the application.
To read text, highlight it and then copy it to the clipboard and press Windows + ArrowDown.