Serializing classes between Silverlight and .NET 4

I’ve realized that I didn’t detail how to ensure you can serialize your own classes between Silverlight and .NET 4 using my SilverlightSerializer class. 

The vital thing to do in these circumstances is to define the classes you want to share in a Silverlight assembly that only references System, System.Core and mscorlib.  These are the requirements for assemblies that can be used in both types of project.  If you define your classes in this way then they can be deserialized on the back end without a problem, reference anything else and it won’t work.  Fortunately most of what you will need is included in those system assemblies!