Contact lists and microformats

I'm playing with the idea of a centralised service that would store/group/aggregate contacts. Someone would create a Contact List that comprised of Contacts and then publish it, giving it a name/uri/whatever.

People could then view that Contact List and see all the Contacts' details. If a Contact changed, all the people subscribed to that list would see the change 'real-time'. Each entity could have a public/private setting that would control access over both the individual Contact as well as aggregated lists.

This solves a real-world problem related to my Bath Youth Rugby project. The club has let's say 50 contacts spread over different age groups/deparments etc; if there are 10 clubs in the region each with 50 contacts that gives us a pool of a 500 contacts - hopefully you can see the admin headache that they have.

Having a central source of contacts would be a really cool solution. Each club could manage and publish their own Contact data (the BYR Contact List) which in turn could be considered a part of a bigger list (Somerset Junior Rugby Contact List). Those with enough "privileges" could then go in an view all the of Contacts within the local junior rugby scene (or some subset based on some access hieracrchy).

I can also see applications of this in the bigger picture of the web/world generally: friends wanting to keep in touch, company positions - heck, any organisation that has any contact data could benefit. Hmn, really interesting :). Slap an API on it and...

Edit: no need to put an API on it as such a list could be formated in XOXO or OMPL. Damn, you've gotta love the semantic web.