Simon

If you want it cheap then in that past I've used Ethereal to get hold of
network traffic including SOAP messages.  Altova do some tools, but at a
price.  Also there's the soon to be desupported SOAP Toolkit...

http://www.microsoft.com/downloads/details.aspx?FamilyId=C943C0DD-CEEC-4088-9753
-86F052EC8450&displaylang=en

The best way we've found is to derive from the SoapExtension class.  This
way you can capture the stream at at various stages of serialisation and
write it out.  It's probably not what you're after right now considering the
apps live and all, but maybe something to think about in the future.

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/frlr
fsystemwebservicesprotocolssoapextensionclasstopic.asp

http://hyperthink.net/blog/CommentView,guid,eafeef67-c240-44cc-8550-974f5d378a8f.aspx

HTH

Glenn