Via Many-to-Many: Marc Canter is is working on PeopleAggregator.com (link not working at time of writing - it's still in alpha). The service supports handles and pointers to multiple services, using FOAF for profile information. Another key feature is private FOAF files, where the user controls who gets access. This will be key to getting people to fill their FOAFs with more than just basic profile data.
The site seems to be down now, but I can't wait to take a peek and learn more...
