Here is how I would like to define relationship permissions to content on social networking sites like Flickr.
In the first image I am assigning someone to a particular friend group. In the second image I'm telling the system which outer-most friend group I want to be able to access newly added content.
Something about selecting cones of permissions this way interests me. I would even like to use it to define severity of bugs, immediacy of problems, or even estimating the magnitude of difficulty something might have.
Oh neat: Caterina, one of the founders of Flickr, responds with some background on this idea and how it is not really a good way to define permissions. Nice to see that someone actually did it. I still think it'd be a nice UI feature for selecting magnitudes.