SD PHP uses UserVoice as a way for members to post topics and vote on what topics they want to hear about.
Please take a moment to go there and post a topic you would like to hear about. While there, look through the topics that have been proposed and vote on ones you want to hear.
Also, please contact us and let us know if you are willing to give a presentation. You do not have to be an expert to give a presentation, just a desire to share any knowledge you have. I know I learn more about the topic I am presenting on every time I give one.