/application/helpers/Gravatar.php

<?php

/**
 * Gravatar View Helper
 *
 */
class Unodor_View_Helper_Gravatar extends Zend_View_Helper_Abstract
{

   /**
    * Vytvari gravatar
    *
    * @param string $email Emailova adresa
    * @param int $size Rozmer gravataru
    * @param string $type Druh gravataru
    * @return string Html kod gravataru
    */
   public function Gravatar($email, $size = 30, $type = 'identicon')
   {
      return '<img src="http://www.gravatar.com/avatar/' . md5($email) . '?s=' . $size . '&amp;d=' . $type . '" alt="gravatar" class="gravatar"/>';
   }

}