UML tool?

Is there any good free UML tool to be used in Part II?
Thanks

Poseidon http://www.gentleware.com

Thanks Thomas. It looks like only the Community Edition is free. Is it enough for the project? Have you used it before and how do you like it?
Thanks again,
Bill

Poseidon is ok for the class and component diagrams but has problems with sequence diagrams.

There were people who used Poseidon CE for SCEA partII (and passed). I missed the interface lollipop, maybe there is a workaround to draw it. So I used trial versions of TogehterControl for component ans sequence diagrams and Rational Rose for the class diagrams.

What do people do with the Poseidon CE watermark? Ignore it? Remove it with some other tool?
I am currently looking at the GPL (free) Violet which is written in Java.
So far it looks like it will be OK for SCEA part II except for Component diagrams. But I had a play this afternoon, and I only needed to write one class in order to add the Component symbol, so I think I should be able to use it for that as well.
Regards, Andrew

Does anyone know what kind of format Sun expects when you submit PartII?
Thanks
Bill

Any good study books or resources for Part II?

i get the impression that if you download the pro version of poseidon( time limited version ) and use that to load up the project and export the diagrams the watermark background should disapear. the water mark does have community edition mark on it.
don't quote me on that though.