I'm looking for a spreadsheet/template that allows the business-rules (i.e. 'who has access to what') to be mapped, visualized and analyzed.
In the past I have created a couple of these (some even with automation using the O2 Platform), but NDAs prevented me from sharing. So while helping with a set of Python scripts to test TeamMentor's WebServices, I took the time to create a model which I think came out quite well.
You can read about it here: Creating a spreadsheet with WebService's Authorization Mappings and this is what it looks like:
https://docs.google.com/a/owasp.org/spreadsheet/ccc?key=0AhHDFVmo550OdDZUcDU5eXpGVGFKWDZjS3VGUHdUTXc

Since I'm going to integrate this with O2 next, it is easier to change it into a better format/standard now (vs later).
I also think that we should have a couple of these templates in an easy to consume format on the OWASP Wiki (I have lost count the amount of times that I have tried to explain the need for 'such authorization tables/mappings' without having good examples at hand).
Note that creating these mappings is just one part of the puzzle! Also as important is the ability to keep it well maintained, up-to-date and relevant.