In my saga of abandoning WCF and regressing back to an ASMX web service for a current project I had a very knowledgable web service person from a telecommunications company send me an invaluable tool for testing webservices.
The cool thing is you can mock web service request, or even send soap request to a webservice through soapUI. The tool has a gazillion features that I haven't even scrated the surface of yet.
I highly recommend it. At first you will open it up, be a little bummed that it is written in JAVA, and you will come to an inteface without knowing really how to proceed. Download a WSDL from a web service and save it, then in soapUI create a new WSDL project and load your local version of the WSDL. You will see how valuable the tool can be.
There is a Pro version with more features, though I haven't checked that out.