How to deal with people looking at their mobile phone during my presentation?
My attitude to life is to spare my mental capacities to things I can affect and change. Yes, it is annoying to see people at a workshop not paying attention. No, there is nothing I can do in the moment that would (i) change their behavior, while (ii) not make me look petty.
So, disengage from these feelings. Focus on those members of your audience who pay attention and interact with you. Make a resolution to have a great first slide for your next talk that may sway one of the two (or maybe both!) to get pulled into the talk. These are the things I can affect.
I'll offer a dissenting point of view.
I often use my mobile device (smartphone, laptop, whatever) during a talk - because I'm taking notes on it!
I used to write my notes on paper, then transcribe them to my giant brain dump TXT file (very easy to search through, which is why scanning is not a solution)... until I noticed that I always put off the transcribing part until I had lost my paper notes. Since then, especially if a talk is relevant, I have been taking notes on my phone, so I can copy & paste the notes directly into my TXT.
Don't immediately jump to the conclusion that people fiddling with their electronics are not paying attention.
(If I'm using my laptop, I'll sit in the back, since I know that my keyboard can be distracting.)
If you are presenting a topic and the audience do not take advantage of your experience and knowledge, it is their loss and not yours. However, two things came to my mind about this topic:
Make Your Presentation More Interactive: I'm not saying to bring big amplifiers and blast music and throw free t-shirts at the crowd, however you can engage the audience with the topic you are working on. You can ask them questions, about their prior knowledge about the topic, and build the presentation around that. If the presenter is looking at the ground, not paying attention to the audience, or not asking any questions, then they won't get the respect they deserve.
Don't be Judgmental About the Audience Behavior: Don't be an insecure presenter, and think negatively right away why the audience do this or that. Maybe they were tweeting how good your presentation is. You don't know what they are doing, so don't waste energy on why the audience is doing this or that, you are the captain in that room, and you should take control of your presentation and audience at the same time.