The Google Data-Vocabulary Ontology
A piece of the FOAF Ontology
You can view Freebase Types/Properties as RDF Schema as well:
Types & Properties in the /people domain
Types & Properties in the /location domain
For added fun, point Protege at these URIs!
http://rdfvocab.freebaseapps.com/rdfsvocab?namespace=http://rdf.data-vocabulary.org/%23
http://rdfvocab.freebaseapps.com/fb2rdfs?domain=/people