//This is the createAction

          if ($userForm->isValid($_POST)) {
                $userModel = new Model_User();
                $userModel->createUser(
                        $userForm->getValue('email'),
                        $userForm->getValue('password'),
                        $userForm->getValue('url'),
                        $userForm->getValue('responsable'),
                        $userForm->getValue('role')
                );
                $paises = $this->getRequest()->getParam('pais');
                $userId = //what should I have here??

                return $this->_forward('list');
            }

//and this is the model

class Model_User extends Zend_Db_Table_Abstract {
    /**
     * The default table name
     */
    protected $_name = 'users';

    public function createUser($email, $password, $url, $responsable, $role)
    {
    // create a new row
        $rowUser = $this->createRow();
        if($rowUser) {
            // update the row values
            $rowUser->email = $email;
            $rowUser->password = md5($password);
            $rowUser->url = $url;
            $rowUser->responsable = $responsable;
            $rowUser->role = $role;
            $rowUser->save();
            //return the new user
            return $rowUser;
        } else {
        throw new Zend_Exception("El usuario no se ha podido crear!");
        }
    }
}