That's Web 2.0 with chocolate flake and raspberry sauce topping (see Wikipedia entry).
[PS. You need to tweak Firefox settings to avoid cross-site restrictions, see the FAQ]
Essentially you point it to your FOAF and schedule data, amongst other things it figures out who you can meet with shared interests at the events you're attending. It does things like going looking for more data for you. Etc. Check this screenshot.
This app flips the chicken and egg situation a little around FOAF - there is loads of FOAF data on the Web, but not many interesting tools to make use of it. This calendar demo is begging for that data to be further enriched to add details of the persons interests, and for people to p ublish their schedule and event info (using iCalendar, microformats or direct RDF).
What would be helpful would be some instructions on how best to publish this stuff for the benefit of the demo (that's another reason I wanted to get my own data sorted, so I could post a walk-through).
Although the app is immediately useful, it's also "an exercise in writing non-trivial SPARQL queries to integrate disparate data sources in answering domain-centric questions". This kind of integration and querying has absolutely huge potential. There's discussion of specific issues raised on the ESW Wiki.
Looks like there might be a long hot summer ahead...@en