Alessio Soldano and me have just released as web application(seam) an open source generic client for web services.
The idea is to generate on the fly rich html form (structuring data as tree) for soap request and response. The aplication is designed to be used also by non-programmer people (QA tests)
It is an alpha quality code, but it seems to work with a lot of webservices deployed on http://jbossws.demo.jboss.com:8080 (for Heiko: we fixed it :) ).
We wrote the core more than 2 years ago for an internal project (based on wsdl4j and, now, some jbossws apis). Now we refactored it to beautify the user interface and we are releasing it with LGPL because we think it could be useful for a lot of people.
If you want to take a look we have deeper description, screenshots and an onlinedemo on www.javalinuxlabs.org. We have created a user jbwsdev/jbwsdev with already registered some wsdls taken from jbossws.demo.jboss.com with a comment for non-working ones.
BTW on www.javalinuxlabs.org we have also an online demo of LMS, another service we developed (Web based Tcp Monitor like tool) and discussed here some weeks ago: