I am the co-organizer of the Dallas PHP group, so I find myself speaking often there.  I have spoken at a few conferences and at uncons like Barcamp Dallas.  Below is a list of presentations I have given, along with a link to the slideshare presentation.  If you would like to have me speak at your conference/event please contact me.

Presentations
Title: CSS Selectors: The Next Generation
Venue: HTML5.tx
Date: 10/8/2011
Slides: http://speakerdeck.com/u/jakefolio/p/css-selectors-the-next-generation

Title: Unsung Heroes of PHP
Venue: Lone Star PHP
Date: 6/11/2011
Slides: http://www.slideshare.net/jsmith92/unsung-heroes-of-php

Title: Intro to Micro-frameworks
Venue: DallasPHP
Date: 4/12/2011
Slides: http://www.slideshare.net/jsmith92/intro-to-microframeworks

Title: Doing more with LESS
Venue: DallasPHP
Date: 12/14/2010
Slides: http://www.slideshare.net/jsmith92/more-withless

Title: SPL: The Missing Link in Development
Venue: DallasPHP
Date: 7/13/2010
Slides: http://www.slideshare.net/jsmith92/spl-the-missing-link-in-development

Title: PHP 5.3 Overview
Venue: DallasPHP
Date: 6/8/2010
Slides: http://www.slideshare.net/jsmith92/php53-5091210

Title: LESS is More
Venue: Barcamp Dallas
Date: 8/21/2010
Slides: http://www.slideshare.net/jsmith92/less

Title: Drawing the Line with Browser Compatibility
Venue: Confoo
Date: 3/10/2009
Slides: http://www.slideshare.net/jsmith92/browser-compatibility