DataLibre from Steve Mallett. It's mission is to: Liberate Your Data, Write Once - Read Everywhere and nicely aligns with the kinds of things FOAF and DOAP are doing for people and projects respectively; which are linked from the site.
It's something I've been interested in and over the
years, had less interest in giving my data to
that then go lock it up, and/or sell it.
This first happened with IMDB (although
it's still available, you can't use it for anything interesting),
CDDB and continues with various subject-specific data aggregators
for blogs and pictures. There are however, some recent
good sites that do let you put
data in and out nicely, with no lock-in such as
bloglines. We need
to do more to encourage this; plus encouraging them to
provide RDF import/export as appropriate.