The so called 'Semantic Web" is a bad name as it implies that such a
thing exists. Semantics are everywhere, whether explicit or not. I
would suggest working on some well scoped projects that require input
from people such as yourselves. There are two happening over at the
Ontolog Forum, a units of measure ontology and a registry-repository
project.
Additionally, volunteering to work on some projects via this group
would probably result in a few people asking you for your help.
Good luck
Duane Nickull