Loading WebFonts via TypeKit: http://blog.typekit.com/2011/05/25/loading-typekit-fonts-asynchronously/

custom.html

  <style>.wf-loading{visibility:hidden}</style>

  <script type="text/javascript">
    (function (doc) {
      var config = {
        kitId: 'abc1def',
        scriptTimeout: 3000
      };

      var getElement = function (tagName) {
        return doc.getElementsByTagName(tagName)[0];
      }

      var htmlElement = getElement('html');
      
      var timeoutCallback = setTimeout(function () {
        htmlElement.className = htmlElement.className.replace(/(\s|^)wf-loading(\s|$)/g, ' ');
      }, config.scriptTimeout);

      var isLoaded = false;

      var script = doc.createElement('script');
      script.src = '//use.typekit.net/' + config.kitId + '.js';
      script.async = true; 
      script.onload = script.onreadystatechange = function() {
        var rs = this.readyState;
        if (isLoaded || rs && rs != 'complete' && rs != 'loaded') return;
        isLoaded = true;
        clearTimeout(timeoutCallback);

        try { 
          Typekit.load(config); 
        } catch (e) {

        }
      };

      doc.head.appendChild(script);
    })(document);
  </script>

typography.js

<script type="text/javascript">
  (function() {
    var config = {
      kitId: 'abc1def',
      scriptTimeout: 3000
    };
    var h = document.getElementsByTagName('html')[0];
    h.className += ' wf-loading';
    var t = setTimeout(function() {
      h.className = h.className.replace(/(\s|^)wf-loading(\s|$)/g, ' ');
      h.className += ' wf-inactive';
    }, config.scriptTimeout);
    var d = false;
    var tk = document.createElement('script');
    tk.src = '//use.typekit.net/' + config.kitId + '.js';
    tk.type = 'text/javascript';
    tk.async = 'true';
    tk.onload = tk.onreadystatechange = function() {
      var rs = this.readyState;
      if (d || rs && rs != 'complete' && rs != 'loaded') return;
      d = true;
      clearTimeout(t);
      try { Typekit.load(config); } catch (e) {}
    };
    var s = document.getElementsByTagName('script')[0];
    s.parentNode.insertBefore(tk, s);
  })();
</script>