Just a heads-up on a complication I found. I created a class to be my message inspector on the Silverlight client-side and I find that the IClientMessageInspector interface does not exist.
http://forums.silverlight.net/forums/p/112429/277355.aspx shows how to manually add and get headers on both sides. So it may be that after all my worry and study that I don't need to write WCF behaviours at all. Although this technique is a bit cumbersome to code. Greg
