Linkify.jquery.js

// Define: Linkify plugin
(function($){

  var url1 = /(^|<|\s)(www\..+?\..+?)(\s|>|$)/g,
      url2 = /(^|<|\s)(((https?|ftp):\/\/|mailto:).+?)(\s|>|$)/g,

      linkifyThis = function () {
        var childNodes = this.childNodes,
            i = childNodes.length;
        while(i--)
        {
          var n = childNodes[i];
          if (n.nodeType == 3) {
            var html = $.trim(n.nodeValue);
            if (html)
            {
              html = html.replace(/&/g, '&')
                         .replace(/</g, '&lt;')
                         .replace(/>/g, '&gt;')
                         .replace(url1, '$1<a href="http://$2" target="_blank">$2</a>$3')
                         .replace(url2, '$1<a href="$2" target="_blank">$2</a>$5');
              $(n).after(html).remove();
            }
          }
          else if (n.nodeType == 1  &&  !/^(a|button|textarea)$/i.test(n.tagName)) {
            linkifyThis.call(n);
          }
        }
      };

  $.fn.linkify = function () {
    return this.each(linkifyThis);
  };

})(jQuery);