Good post. I solved my mongo full text search problems 2 weeks ago using Ruby's Sunspot gem <a href="http://outoftime.github.com/sunspot/" rel="nofollow">http://outoftime.github.com/sunspot/</a>.<p>I walked through this tutorial <a href="http://masonoise.wordpress.com/2010/02/06/using-sunspot-for-free-text-search-with-redis/" rel="nofollow">http://masonoise.wordpress.com/2010/02/06/using-sunspot-for-...</a> on using Sunspot with Redis and had it working with Mongo in under an hour.
For production ready, scalable FTS, you might be interested in Lucandra: <a href="http://github.com/tjake/Lucandra" rel="nofollow">http://github.com/tjake/Lucandra</a>, which powers the <a href="http://sparse.ly/" rel="nofollow">http://sparse.ly/</a> twitter search site.<p>Higher level overview of Lucandra: <a href="http://blog.sematext.com/2010/02/09/lucandra-a-cassandra-based-lucene-backend/" rel="nofollow">http://blog.sematext.com/2010/02/09/lucandra-a-cassandra-bas...</a>