I have been following Simon Sinek for about 2 months and have watched about 30-40 of his clips many times.
He has a great message about changing the future and I encourage as many people to study his videos.
I recently ordered his book, "Start With Why" and I'm looking forward to reading it.
Start with Why: How Great Leaders Inspire Everyone to Take Action: Simon Sinek: 8580001042060: Books - Amazon
This is his home page and I suggest to watch all his videos on his site as a place to start.
This video is the third highest Ted Talks ever and is a good video to put at the top of the list.
Simon talks about the addictive use of cell phones and digital media. From other sources they call them Digital Zombies or Mobile Zombies and I see them on the buses on a regular basis.
Simon Sinek - BE A INFINITE PLAYER - ONE OF BEST SPEECHES EVER By Simon Sinek - Wake Up Motivation - YouTube
This is just a small collection and I tried to use links with no advertisement inserted into the video.