I have written a set of Web services in VB.NET at work. Well the clients for the web services are actually programmed in PHP, but it seemed like a good idea to test that the VB.NET SOAP based web services were able to be contacted from another language and since I had to deliver functional tests for the operation and maintenance department any way, I decided to use Perl.
Write a few small scripts in Perl using LWP and SOAP::Lite was quite easy, but since I had to be able to test many web services in a simple manner, I came to think of using Perls test framework Test::Harness.
So now all by functional tests for the VB.NET web services are written as Perl tests, making them VERY flexible, easy to extend and with a nice interface which will be familliar to the guys in O&M...