I've worked a bit on the Visio Stencils I'm using for documenting Site Structures and I fixed the way "text" works with the Site Structure stencil. You can now simply double-click on it and the text will be correctly modified (not added over it) (note: The icon "Text Block Tool" in Visio is your friend there and very customizable and easier to use). Also, the connectors will work better since it's only detecting the "rounded" icon and I included some of the built-in Visio annotations & connectors that are essential to a good documentation.
Basically, when I do MOSS documentation, I will be doing a complete Site Structure architecture, a Page Layouts (stencil coming soon) documentation, or a server/environment layout. As mentioned in my earlier blog post, the servers are covered on this other blog.
** UPDATE ** : I updated the links since the free file sharing service I used has apparently been hacked.
Here's the link to the stencil on my Live SkyDrive :
This is a quick sample of what you can do for a Site Structure with the previous stencil :
I will finish the Page Layouts stencil and post it a bit later. Cheers!