Unvisit Firefox add-on
A simple Firefox add-on that uses the unvis.it service to read the relevant content from sites without visiting them. This add-on lets you rightclick any URL and visit it through unvis.it. Works best on sites like news sites and blogs, but might work on other sites also. It doesn't work on all sites.
Install from https://addons.mozilla.org/en-US/firefox/addon/unvisit/ or just download the .xpi file direcly, open Add-ons and choose "Install from Add-on from file..." from the menu.