New Module: Menu per Role
I've just created a new module: Menu per Role
This module allows you to restrict access of menu items per roles. It depends on the drupal core menu.module - just activate both modules and edit a menu item as usual. There will be a new fieldset that allows you to restrict access by role.
Unfortunately the module requires a simple patch for drupal's menu.inc.
So finally creating menu items for only a special role is possible through the admin interface. :)