A quick heads-up: my 2-part article series on authorized navigation in Silverlight has been published at SilverlightShow.
The first article tackles authorized navigation: allowing or refusing access to a certain page/View in your Silverlight application depending on the role of the user.
The second article concerns authorizing access to certain UI elements IN a View (instead of the complete View), depending on the role of the logged in user, and deciding what to do when the user hasn’t got the correct role (eg: do you want to disable the element, or do you want to hide it completely?).
The complete source code is included in both articles.
Update: a third part has been released, focussing on securing your service calls.
Happy coding! 🙂