Need to define "Person"in your local ontology? Unless you want to add yet another identifier for this concept, your contribution to the Semantic Mess, go ask Swoogle Ontology Dictionary and pick up your choice. At first ranks come with no surprise classes from FOAF http://xmlns.com/foaf/0.1/Person and WordNet http://xmlns.com/wordnet/1.6/Person.
But there are about 400 other SW resources, classes and properties using the same name. Food for thought ... Why so many already? What about re-usability? What about aggregation of data and federation of knowledge? (see previous post) How many of those resources declare equivalence with other ones? And how many are actually used?