Probably my favorite solution right now for Rx is to use it as an event aggregator. Take a look here:
http://jfromaniello.blogspot.com/2010/04/event-aggregator-with-reactive.html
I adapted this to Silverlight and it works like a charm. What is amazingly powerful is the ability to filter events. For examle, one event is just type "string" because there is no other information. Instead of creating a strongly typed class for each simple event, I created a class that exposes the constants (so there are no magic strings) - for example, BEGIN_BUSY (when a web service is being called), END_BUSY (when it's done), etc.
To subscribe, you can literally do:
(from e in EventAggregator.Subscribe() where e.Equals(BEGIN_BUSY) select true).Subscribe( evt=> { // Listening only to the BEGIN_BUSY event });
Love it!
