EROS "EROS is a graphical java-based user interface for browsing RDFSchemas and for expressing (RQL) queries over these." The querying (by example) seems to be a bit more user-friendly than most and it uses Sesame (makes a change from Jena!).
A few write-ups are available: EROS: A User Interface for the Semantic Web, Bringing the Semantic Web closer to the User, and EROS: Explorer for RDFS-based Ontologies.
From the Hera project.