At various times I've looked into FOAF but never quite groked what it could mean for me. Interesting technology to be sure, but so what?
An entry on Jess' weblog, Nice Font You've Got There just made it 'real' for me, at least as far as I understand it.
Jess and I have been friends and coworkers for several years now. Cory and I know each other, having met at OS X Con and SXSW. We share some common interests stemming from his work at the EFF and my history with the Computer Underground.
Had Jess and Cory exchanged FOAF files (in addition to fonts) they would have discovered me as a person-in-common, instantly providing for conversational fodder, discovery of common interests, and some degree of whuffie assessment.
Or, maybe not. At least I think it's an example of where FOAF could be useful.