Another revision, after feedback from Ivan.
The original had “Thing” in italics (a convention I tried before adding in doap: dc: and sioc: references), to indicate it was from another namespace. I’ve now made that heritage explicit (although I suspect it might confuse, the idea is pretty central so worth explaining).
Originally I had both “tipjar” and “mbox” drawn as if they were literal properties, when both are relational. The later layout I’m using allows tipjar to be drawn without crossovers, so now only “mbox” is an oddity. I’ve used italics as a hint of that, but without explicit explanation.
A lot of the redundancy in the diagram comes from the property inverses, but I want to leave them in since they’re important to explain. The expanded key in the bottom-left now has a nerdy little explanation of “inverse property”. I also use the word “subClass” explicitly on the fat arrow, to tap into an OO heritage that might be floating around in people’s minds. In other words, I want people to realise that “a Person is an Agent is a Spatial thing is a thing” is what we’re getting at with those fat little arrows.
On Ivan’s suggestion I trimmed the property lists a little. Removing the non-jabber IM properties, and first/last name. The space earned from the latter was immediately spent by adding in bio:olb since it’s useful and I’ve the impression it’s widely used.
I think that’s about it for changes. Ivan suggested removing the DOAP and SIOC partys, but to my mind they are important because those vocabularies (and projects) elaborate on parts of FOAF which are important but otherwise neglected: the description of Projects, and of Users.
OK one more version. This has coloured blogs for the core FOAF classes. I think I made a mistake choosing light blue, since that is the colour code I’ve assigned to mean “inverse functional property”, nearly. Perhaps a light yellow?
Anyway here it is for now. Guess I should stop using Flickr for this really!
Update: I’ve put the files in svn (original OmniGraffle XML is the .graffle file; also some SVG output although I’m unsure the quality), and made another slight revision, this time focussing on the layout of the ends arrows for better readability; previously they were cluttered and the property directions were therefore hard to read.