Q: How can I examine the contents of a SOAP envelope generated by my own proxy class?

A: Take a look at what this clever guy figured out how to do:

How to capture SOAP envelopes when consuming a web service in ASP.NET.

He used the SoapExtension class (http://msdn2.microsoft.com/en-us/library/system.web.services.protocols.soapextension(VS.80).aspx)

to add logging to the proxy class, and viola! Cool, eh?