Fred from TalkDigger has an interesting post on FOAF profiles.
The idea is for each service you register with to ping your FOAF file, that way any updates to your profile (eg. move to another country) will happen automatically for every service you are registered with.
Since OPML is being used for a few different purposes, it could also be used for something like this, the service could subscribe to your OPML file/URL…all you ever have to do is update your OPML and everything does like wise.
I understand that FOAF is a dedicated service for social networks, but since people are becoming savvy with OPML, there’s no reason OPML can’t be used as simple profile.
RSS for contact information
[ADDED 29/05/06: James Corbett is posting along the same lines]