GeoIP Role allows to dynamically grant roles to the current user according to his IP address location.
It depends on the GeoIP API module.
Currently, GeoIP Role allows to attach countries to roles, thus defining geographical zones.
When a user visits your site, he dynamically gain the role(s) attached to the country reported by his IP address.
GeoIP Role may be used with any other module like Nodeaccess that controls access based on user roles.
Have you ever needed to hide the local task tabs? Typically, you override theme_menu_local_tasks() and, based on some condition, return an empty string.