I find that the form and layout of content in most webpages is detrimental to a distraction-free reading. Bad fonts are used and the content is squeezed in between photos, advertisements and links to other articles. So, for quite sometime now I have been using bookmarklets in Firefox that rendered the text content of a webpage in a distraction-free form for reading. At first I was using Readability and when it felt slow I switched to Readable. The latter has recently been bought by Evernote and has been repackaged as Evernote Clearly.
Both of the above solutions are fine, except that they both have a bit of latency when applied on a webpage. Thankfully, there are now Firefox addons that provide this same feature and I have been happy with one of them: Reader. This is based on Readable, and is much faster in rendering the content of a webpage. It uses a convenient shortcut too:
Ctrl + Alt + R, R is for reading! To change the font, background color and other properties of its content display, just click its icon in the addon bar at the bottom of Firefox.
Tried with: Reader 2.1 and Firefox 9.0