There’s been some questions floating through the Pentahoshpere (I think I’m the first person to use that word, btw) about how to use Subreports. I think there’s a good description at the wiki that covers the basics, but I don’t think there’s a good working example that is shipping with Pentaho open source yet.

I don’t really have time to delve into all of it so in the spirit of “early and often” I’ll just post the zip file with a working example (on 1.6 GA Designer and Server).

Here tis:
http://nicholasgoodman.com/entry_images/pentaho_subreport_example.zip