MSN->FOAF can be done via msnm-lib
Jabber Roster -> FOAF can be done via Jabberbeans (although I’d prefer to use somthing like Smack because Jabberbeans is so hard to just get started with, Smack, on the other hand, is a delight)
Obviously JID -> FOAF entry can also be done using JabberBeans.
But what’s the point? FOAF is a nice use of RDF in the real world, but I’m not writing an RDF parser (I’d use Jena if I was), and I’ve not yet seen any great uses of FOAF profiles (yes I’ve seen FOAF-a-naut and so on), but GeoURL is better for locating people who live close to you and things like the blogging neighbourhood are better for finding people’s sites you might like to read. In fact, the best thing I’ve seen done with it so far is Mark Pilgrim’s ‘About’ page, which is generated directly from his FOAF file. But while this is a neat use and exercise in RDF manipulation, it doesn’t really serve any purpose.
What FOAF needs is for someone big to start using it, productively. There’s a Movable Type plugin that lets you enter the URL of your FOAF file and it fills in the relevant comment boxes for you (name, URL, email address), which is cute, and, I’ve not looked into but, but if it supports standard autodetection (via the link tag), you’ve only got to enter the normal URL of your website.
What we really want is Amazon to use it though. Register? No need — here’s my website, find my FOAF file and get all my info from there. Amazon then becomes one-click registration (and you know how much they love their one-click systems), and others must surely follow. Security worries (I mean, how do you know the user is who the FOAF file says they are?), sign your file.
Obviously this then gives you a web-wide secure digital signature, all based on open source, human-readable techo-babble, which is probably not how it was intended, but wouldn’t you like to see people use that instead of MS Passport? (btw, I’ve heard the Liberty Alliance has fallen apart, is this true?)