Sample ontology/datasets

Hi,

I'm a developer (still) trying to get into semantics. I like very much
TMs, but there also need to use RDF for some purposes. I'm actually
trying to build an abstract ontology (it is really the model for an
index) and I'm needing sample data in any format (TMs, RDF, SQL, CSV,
etc) to try out the mappings and if I can go from/to the data formats
and my actual entities (import/export). Any sources information will
be appreciated. Regards,

Sebastián Samaruga
http://cognescent.blogspot.com