Visio 2003 uses UML 1.4, which means that some stereotypes from UML 2.0 simply don\'t exist, and they need to be modeled by freehand drawing (I may as well be using Photosho
The nice thing about Visio is that it is just a drawing program and not a modeling environment. So just make up your own lines. Visio can draw just about any line time you can think of. But the real answer is the one already checked. Now that Microsoft "supports" UML maybe they will provide better tooling.
I found this package: http://www.sdl.sandrila.co.uk/ but judging by their "example" screenshots, I'm going to stay away. If they don't know how to use UML, I'd be surprised if they could implement it correctly ;)
That seems a bit harsh - of the handful of screen-shots which are UML2 (as opposed to being examples of the other notations the tool supports, such as SDL, MCL and TTCN), which do you think are incorrect? It's quite ugly as diagrams go, and uses aliased fonts and lines, but that's a Visio feature rather than anything to do with the template.
In terms of what you can do with the UML, you are much better off using a real UML2 tool than Visio. Enterprise Architect is a cheap one which does have a real UML model behind it. (It would be nice to be able to say that the more expensive ones have fewer UI bugs and gotchas, but that isn't really the case, and most lag far behind the simpler graphical tools like OmniGraffle or Visio in polish and usability)
I'm using the UML 2.0 symbols from Pavel Hruby. Maybe you'll find them useful as well.
This set of Visio stencils and templates for UML 2.0 is excellent:
http://softwarestencils.com/uml/index.html
In case it wasn't clear, Microsoft will never update Visio support of UML. For some time, they have not considered Visio to be a Software Engineering tool.
I don't blame them. It didn't even do a good job with the parts of UML it "supported".
Those screenshots are only example diagrams, Sandrila SDL doesn't enforce that level of rigour to the diagrams.