This document discusses how semantic web technologies like RDF and SPARQL can help navigate complex bioinformatics databases. It describes a three step method for building a semantic mashup: 1) transform data from sources into RDF, 2) load the RDF into a triplestore, and 3) explore and query the dataset. As an example, it details how Bio2RDF transformed various database cross-reference resources into RDF and loaded them into Virtuoso to answer questions about namespace usage.