Picked this up from orablogs.com this morning.

The many UML editors have a lot of whizbang features. Useful for sure, especially for environments that are heavily building intricate applications using methodologies that benefit from using the varied UML diagrams (Activity, Collaboration, Component, Deployment, Model Diagram, Sequence, Statechart, Static Structure, Use Case).

In practice, most of us use just a few and use them in a reptitive fashion. Build a sequence diagram that documents a use case, print it, include it in documentation. Repeat for all 10 use cases. In my humble opinion, doing repetitive tasks in a gui is time wasted.

Consider using this tool rather than mess with a GUI for building simple sequence diagrams. Since it takes text as input, you can even run your current .java files through it to render HTML.
It generates the image for documentation, and since the “graph” is actually just a text file one could check it into CVS. I’ve not worked on Java for some time now, but if I ever need to get back on that bicycle, I’d strongly consider using a “UNIX shell programmers” UML tool.