OK, I was sitting in my seat from LAX to SLC, they were close to closing the door for pushback and I went to turn my phone off. I then realized that I did not have my passport. I barely made it off the plane as they closed the door as soon as I was out. So, quick thinking, I used my passport to get through security so it had to be between security and the gate. I doubt that I dropped it so I went to security. Luckly they had it. I must have missed it when grabbing all my stuff out of the plastic bin. Only bad part was now it was another 3.5 hour wait for next flight, but passport much more important than catching the flight.