Hello Lucas!

Another advantage of using RDFa is that you can mix-and-mash other information alongside licensing information – for example, you could state a list of contributors for that particular media file, or any other things that terms in DC, Music Ontology, FOAF etc. allows you to express.

I guess (I don’t really know as I didn’t have time to play with it yet) that searchmonkey can help to build search applications on top of such RDFa – such as finding works by a specific person who have a particular license.