As part of the MSDN connection program offered by Microsoft here in Australia, I believe that all dedicated level developers received a copy of Borlands "Together" for Visual Studio.Net. An addin that lets you do UML modelling synchronised to source code. It comes complete with a patterns repository and other features. I wasn't too interested in synchronising source code but loved the idea of integrated UML modelling in VS.Net. I like UML and use it constantly to describe class designs and system designs for a lot of our detailed design documents we need to produce, as well as to simply describe a class design for developers in my team to work towards. (Note: If you dont use UML for your design work, I recommend you start, even if its just to describe class heirarchy and design for yourself)
While it certainly allows one to do all that is mentioned above, its not as nice as I would have hoped.The print features simply dont work properly, I ask it t print a class diagram, and 2 class models come out on one page, with the rest of the diagram on another page. Also, the code sync features seem to have some wierd effects in that occassionally, association lines would disappear and had to be redefined. Finally, sometimes I just dont want to enable the addin for every single project, particularly for large projects where it wasn't initially used. While there is an option to cater for this, it doesn't seem to always work as expected and I find myself disabling the option again and again.
I love the concept that this product tries to address and I it certainly has a good feature set, but still seem to be somewhat lacking in some areas of its execution.
I'd love to hear of other tools that people use for this that are integrated into VS.Net. Visio and Rational Rose are fairly well known but I'd like to know from others experience.
One final note, the MSDN connection program in Australia is a great initiative from Microsoft and the support shown to Australian developers is great. For more information, see Frank Arrigo's blog.