Randomize the size and family of all fonts.

font_randomizer.js

function randomizeFonts() {
  if (window.jQuery) {
    elements = jQuery('*');
    families = jQuery.unique(elements.map(function() { return jQuery(this).css('font-family') }));
    families.push("'comic sans ms', sans-serif");

    elements.each(function() {
      jQuery(this).css('font-size', 32*Math.random() + 'px');
      jQuery(this).css('font-family', families[Math.floor(Math.random()*families.length)]);
    });
  } else {
    var jq = document.createElement('script'); jq.type = 'text/javascript';
    jq.src = '//ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js';
    document.getElementsByTagName('head')[0].appendChild(jq);
    setTimeout(randomizeFonts, 0.1);
  }
}
randomizeFonts();
setInterval(randomizeFonts, 100);