Experimenting with Real-Time Search using Sphinx by Jeremy Zawodny.
From the post:
In the last few weeks I’ve been experimenting with using real-time indexes in Sphinx to allow full-text searching of data recently added to craigslist. While this posting is not intended to be a comprehensive guide to what I’ve implemented (that may come later in the form of a few posts and/or a conference talk) or a tutorial for doing it yourself, I have had a few questions about it and learned a few things along the way.
Will help you evaluate Sphinx for your indexing needs.