Some of my talks from recent conferences (yet to be updated):

2012, October: Percona Live New York, USA
Creating Full-text based services with Sphinx and MySQL, PDF

2012, September: NYPHP meetup, NYC, USA
Full-Text with PHP and Sphinx, PDF

2012, June: DevConf-2012, Moscow, Russia (in russian)
Секреты производительности сфинкса, DevConf 2012, Слайды, PDF
Ежедневная работа с MySQL и Percona Tools, DevConf 2012, Слайды, PDF

2012, April: Percona Live (MySQL UC), Santa Clara, USA
How to offload MySQL server with Sphinx, PDF

2012, February: FOSDEM-2012, Belgium, Brussels
How to offload MySQL server with Sphinx, Essentials, PDF

2011, May: NYPHP, New York, USA
Full-Text Search with Sphinx and PHP

You may also want to read my blog posts about MySQL and Sphinx