Finding friends with XML and RDF is not new but rising while weblogs get spread around. Edd Dumbill wrote an article [1] in June 2002. You can use that form [2] to produce your own FOAF.
[Update] Edd Dumbill has also an interesting page on FOAF [3].
[1] http://www-106.ibm.com/developerworks/xml/library/x-foaf.html
[2] http://www.ldodds.com/foaf/foaf-a-matic.html
[3] http://usefulinc.com/foaf
