Hi Mark,
If you want a good UML tool (so long as you're using Windows) it's hard to go past Enterprise Architect, see http://www.sparxsystems.com.au/ - check it out.
Support the .au product!
If it isn't what you want, check out ArgoUML
(open source).
biv
biv
I've tried ArmoUML, often, its great, but it also quite sucks in places.
The last time I actually wanted to do a diagram of somekind was a
sequence diagram, and ArgoUML - at lest 4 months ago failed badly and doing
one properly.
I'm also more inclined to like the idea of working with a round-tripping UML tool. I remember using BOLD for Delphi ages ago briefly, and seeing the tight round triping was nice.
Does Enterprise Architect have a free/community edition? I'll be downloading the Community Visual Paradigm later today to check out...