James Snell writes about WhoAmI Self Hosted Identities, and proposes a protocol to query a person’s FOAF information through Jabber, and explains how it can be used for by web applications and sites to discover your preferences and interests, without you having to enter them again and again, or have the sites working them out over time (much as sites like Amazon currently do).
The problem appears early on (as they so often do), that this emergent data would need to be stored in some kind of standard fashion so that it’s easily accessible (the information could be stored on your local machine for instance, or a webserver you have access to; you have control over who can see what information and how much, etc.). FOAF is easy, there are fixed fields you can specify, but who can determine what kinds of data systems that use emergent properties will need, or even generate? Some ‘catch-all’ isn’t good enough, and it would take companies working together to surmount this. Something I’m sure that hasn’t escaped the attention of the MS Passport and the Liberty Alliance.
UPDATE: Obviously the answer lies in the semantic web. RDF is the answer to world hunger.