Erik Hatcher has published a Meet Lucene online presentation (slides + audio).
The presentation is a nice introduction to Lucene. There are still a lot of people out there who do not know about this open source gem, and if you haven’t had a chance to check it out, watch this.
One of the best reasons to watch it, is that you learn what Lucene IS and ISN’T. I still find that people assume it is a web crawler, rather than a search API.