This is actually quite helpful, thanks. I did look at neo4j, but I got as far as...

lincolnq on Aug 7, 2009 | parent | context | favorite | on: Riak: A decentralized key-value store

This is actually quite helpful, thanks. I did look at neo4j, but I got as far as noting "this doesn't have queries" before giving up. So thanks for pointing out that Lucene might help with the querying part.