Do you ever feel the need to adjust the font-size of a page ? Just run this code in your Console (Chrome dev tools/Firebug/...) and select some text ! // note that this code was written under 60seconds just to read this post : http://lifehacker.com/a-scientific-guide-to-saying-no-1293242273 Chrome extension coming soon. Maybe.

set-font-size.js

(function() {
  function setSelectedSize(s) {
    var arr = document.getElementsByTagName(window.getSelection().baseNode.parentNode.tagName);
    for(var i=0; i<arr.length; i++) {
      arr[i].style.fontSize = "" + s + "px";
    }
  }

  window.addEventListener("mouseup", function() {
    if(window.getSelection().type == "Range") {
      s = prompt("New font size ?", "");
      setSelectedSize(s);
    }
  });
})();

/**
 * as a bookmarklet
 *
 /
// javascript:(function(){function e(e){var t=document.getElementsByTagName(window.getSelection().baseNode.parentNode.tagName);for(var n=0;n<t.length;n++){t[n].style.fontSize=""+e+"px"}}window.addEventListener("mouseup",function(){if(window.getSelection().type=="Range"){s=prompt("New font size ?","");e(s)}})})();