SharePoint has been getting a lot of attention recently, and I've seen a lot of requests for stencils to help manage its design and deployment. A former colleague pointed me to this post, which includes a stencil that allows you document site structure. The author is working on some additional SharePoint related stencils and includes pointers to stencils others have put together.
As always, a good place to start when looking for domain specific stencils is the download site our MVP's have put together.