Glassfish (http://glassfish.dev.java.net) offers you pretty comfortable way how to control logging. You can find it in it's admin console and Fabian already described what to do to get some fancy logs out of e.g. WS-Policy WSIT framework there in his blog).

However, there is yet another way to configure logging levels for non-glassfish environment.
Simply edit your $JAVA_HOME/jre/lib/logging.properties file.

And if you do not mind you will be overwhelmed with bunch of different logs, just do what I use
to do when want to get some logging stuff quickly and use the following two lines in your logging.properties file:

.level=FINEST

java.util.logging.ConsoleHandler.level=FINEST

When I heard about SOA (http://www.sun.com/products/soa) for the first time, I considered it a really great approach. I had just two doubts about it. I was pretty sure, a lot of functions within the enterprise IT infrastructure at the vast majority of potential customer sites were not ready to be accessed via web services. And the second one, well, it was really hard to believe, that every single existing web service in heterogeneous IT infrastructures, which was (and still is) quite usual at customer sites, could smoothly start communication with each other, without certain testing and possible additional configuring.

Now I am quite happy that I can contribute a solution. Project Tango, which I am part of, addresses both of these issues by introducing not only the implementation of appropriate interoperability standards but also the tooling for it. Detailed information about emerging WSIT (Web Services Interoperability Technologies) can be found on http://wsit.dev.java.net/ site. And because seeing is believing and hands-on testing is even better, I really recommend you visit JavaOne 2006 LAB-4335 hands-on session, which will cover an end-to-end example of all of this amazing stuff.