Concepts that come to mind are:
- role based authentication
- grouping controllers into name spaces [1]
- with_scope [2]
These might not be the best articles, but just to get you started:
[1] http://peat.wordpress.com/2006/06/30/watch-your-namespace/ [2] http://habtm.com/articles/2006/02/22/nested-with_scope
