I was toying with the idea of simple, atomic objects with a limited payload - a block of text, a file, or a reference (typically a URL) - and letting the user bind these together using RDF descriptions (the user will have all the technical details hidden from them of course. It'll be point and click to them.)
And I wanted to test this out by letting anyone come along and make use of it. I looked at Shibboleth for the auth layer, but there are some serious roadblocks to casual hacky use of it, which is part of its design (for better not worse, I might add.)
So, I've turned to OpenID for this demo thingy - Anything that takes away the authent/authorise part of an app is a Good Thing(tm) from my point of view.
Right, how to bind it all together? After asking on irc://irc.freenode.net#swig 'kwijibo' pointed me towards the SIOC namespace - http://rdfs.org/sioc/ns which has handy classes like #Item and #Space, and very handy properties, such as #about, #attachment, #content, #note, #related_to, and #reply_of.
And, due to planets aligning, synchronicity, and all that type of stuff, I am going to implement it as the final part of my tutorial on building a website backed by Fedora-Commons.