In the next part of his Zend_Navigation series Brandon Savage takes a look at integrating it with Zend_Acl to add permissions/roles into the mix, showing certain things for certain users.
What happens when you have special areas of your site, say for subscribers or administrators? Controlling access is something that all web developers must do at some point. This is where integration between Zend_Navigation and Zend_Acl comes in.
He shows how to set up the access control levels for an "Admin" section in an example navigation array. It uses the "resource" and "privilege" attributes to define the group and role that has access to that navigation item. Then, with a "setAcl" call you can pull that information in and the two lines of code to output it.