$.random(*number)

gistfile1.js

(function($) {
  $.fn.random = function(qty) {
    var $pool = this,
        $picks = $(),
        $e;
    qty = qty || 1;
    while (qty) {
      $e = $pool.eq(~~(Math.random() * $pool.length));
      $picks = $picks.add($e);
      $pool = $pool.not($e);
      qty--;
    }
    return $picks;
  };
})(jQuery);