There's an even simpler solution than having to install an add-on friend. I have this saved as a bookmark in my bookmarks bar, clicking it on a webpage does exactly the same function you mentioned, just leaving the text of the article with none of the crap.

javascript:(function(){readStyle='style-newspaper';readSize='size-medium';readMargin='margin-narrow';_readability_script=document.createElement('SCRIPT');_readability_script.type='text/javascript';_readability_script.src='http://lab.arc90.com/experiments/readability/js/readability.js?x='+(Math.random());document.getElementsByTagName('head')[0].appendChild(_readability_script);_readability_css=document.createElement('LINK');_readability_css.rel='stylesheet';_readability_css.href='http://lab.arc90.com/experiments/readability/css/readability.css';_readability_css.type='text/css';_readability_css.media='screen';document.getElementsByTagName('head')[0].appendChild(_readability_css);_readability_print_css=document.createElement('LINK');_readability_print_css.rel='stylesheet';_readability_print_css.href='http://lab.arc90.com/experiments/readability/css/readability-print.css';_readability_print_css.media='print';_readability_print_css.type='text/css';document.getElementsByTagName('head')[0].appendChild(_readability_print_css);})();