Indexing the content of Gene Ontology with apache SOLR by Pierre Lindenbaum.
Pierre walks you through the use of Solr to index GeneOntology. As with all of his work, impressive!
Of course, one awesome post deserves another! So Pierre follows with:
Apache SOLR and GeneOntology: Creating the JQUERY-UI client (with autocompletion)
So you get to learn JQuery/UI stuff as well.