I mentionned about one month ago I wrote a frontend to RAP, called PHOAF, to easilly query FOAF files in PHP5.
Here’s the app I wanted to hack while starting the lib: foafMap, which displays users found in a FOAF profile on a Google Map.
This first version is really basic, but I plan to improve it in the future[1] (avatars, auto-zoom on main foaf user, expanding network …). And, also that’s a bit slow if you know a lot of people, as it fetch and parse each profile.
Yet, I think that’s another fun way to see how Semantic Web can help to share and re-use data among the Web.
Enjoy !