linkify.js

  function linkifyText(string){
    if (string) {
      string = string.replace(
        /((https?\:\/\/)|(www\.))(\S+)(\w{2,4})(:[0-9]+)?(\/|\/([\w#!:.?+=&%@!\-\/]))?/gi,
        function(url){
            var full_url = url;
            if (!full_url.match('^https?:\/\/')) {
                full_url = 'http://' + full_url;
            }
            return '<a target="_blank" href="' + full_url + '">' + url.substring(0, Math.min(full_url.length, 20)) + '...</a>';
        });
    }
    return string;
  }