The following two links won’t do much if you click them now, but if you drag them to your bookmarks toolbar, clicking the first one there while viewing a Wikipedia page will take you to the corresponding DBpedia page, and clicking the second while viewing the Freebase page for a particular topic will take you to the page full of RDF for that topic.
When my TopQuadrant colleague Dean Allemang referred to the use of DBpedia as a controlled vocabulary, I said “Huh?” He helped me to realize that if you and I want to refer to the same person, place, or thing, but there’s a chance that we might use different names for it, DBpedia’s URI for it might make the best identifier for us to both use. For example, if you refer to the nineteenth-century American president and Civil War general Ulysses S. Grant and I refer to him as…
I’ve known for a while about ways to dig into the vocabularies used in DBpedia’s massive collection of triples, and I’ve used terms from these vocabularies to query for information such as Bart Simpson blackboard messages and US presidents’ ages at inauguration. I saw these terms as “field” names to use when querying this body of data.