Previously, I wrote about how to dump Service Message Objects to the SystemOut log using a custom mediation. This solution involved using a small amount of Java code.
In later revisions of WebSphere Integration Developer 6.0.2, and in version 6.1, it is now possible to do this with a visual snippet, which makes it even easier. Place a custom mediation in your flow, and use the ‘Visual’ mode. The key to this technique is the pre-supplied print BO to log visual snippet in the utility section of the standard supplied visual snippets. If you hook this up to the smo input (and add a constant string print for good measure, to make reading the log easier), your visual custom mediation will look a bit like this:

This will provide output similar to that shown in the previous tip.
(Note: in fact, you can use this standard visual snippet to print any Business Object, not just a Service Message Object).