Yes, OWL is a really great thing. A while ago I wrote some small ontologies with it.
I even had the crazy dream of writing on ontology in OWL for the U.S. Code of Federal Regulations, and went as far as making a beginning ontology in OWL for the section on OSHA codes for construction, occupational health and safety standards. There are a zillion very specific safety guidelines in there about everything like boilers, scaffolds, hazardous materials you name it. I thought it would be great to have OWL classes and descriptions of all that and then to be able to organize at least that section of the CFR accordingly. It was a huge undertaking that unfortunately, like with so many things, I didn’t get very far with.
It seems most people frown on making your own ontology, but I believe the original vision was that many ontologies would bloom and some would grow.
For this thing that I blathered about with the collaborative speculation, I would probably use a process like the one described here. If I get that far