I'll be giving a presentation and demo of using Apache Solr with Drupal at the Ann Arbor Drupal User's Group on Monday, September 24th. Here's the description of my talk:

"How do you handle search on large sites like Drupal.org or Economist.com? While Drupal's included search module is sufficient for small sites, it has problems with performance and usability once you get to hundreds or thousands of nodes. Apache Solr is an alternative search system that handles these performance issues and provides user-friendly features like faceted search, content recommendations ("More Like This"), language stemming, and query suggestions ("Did you mean...?").

In this presentation, Wayne will walk through a simple Solr setup for Drupal and demonstrate how to configure the the features listed above. If there's time, we'll discuss more advanced options and additional contrib modules that can extend Solr's functionality."

Update: Slides from the presentation are here: http://wayneeaker.com/a2solr