Yes, menus can be displayed by roles, if you have roles set up correctly you can set all the menu items in the master page and the roles will hide or show the correct
here's a few links
membership : http://msdn.microsoft.com/en-us/library/ff648345.aspx
roles : http://msdn.microsoft.com/en-us/library/ff647401.aspx
http://weblogs.asp.net/scottgu/pages/Recipe_3A00_-Implementing-Role_2D00_Based-Security-with-ASP.NET-2.0-using-Windows-Authentication-and-SQL-Server.aspx
sitemap : http://msdn.microsoft.com/en-us/library/system.web.sitemap.aspx