There is no property or event on the generated client reference class that can be used to identify that an asynchronous call to a method of a Silverlight WCF service is currently in progress . You can record this yourself using a simple boolean variable though, or by using the blocking thread synchronization that you mentioned you want to avoid in this case.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.