A WebmasterWorld thread says that Google has counted links from within Microsoft Word Documents, as links to a page.
We all know Google indexes files like Word Documents, PDFs, and many many other types of documents. We also know you can embed links within Word Documents.
This Webmaster noticed in his links report, that Google included a link from a .doc file.
So I decided to download all my links from Google Webmaster Tools and do a quick find command for ".doc" and presto, I found links from Word files.
Here is one of many examples of a Word document that is online that has a link to me.
Forum discussion at WebmasterWorld.

Comments:
Michael Wilson
08/03/2007 12:32 pm
I didn't know this. Hrmmm makes me think since I have a ton docs. But the outbound links to low PR sites might not be a great idea? Thoughts?
Michael Martinez
08/03/2007 03:45 pm
Don't worry about "outbound links to low PR sites". That's not an issue with Google. It's just another SEO myth that gets passed around in the SEO forums and blogs.
Mike
08/29/2008 06:28 pm
Do common 'keyword spamming' flags count with docs, like keyword density and so forth, do you know?