If you've been in an airport since 9/11, you know about all the hoops that you have to jump through before you even get to the gate. The last time I flew, I was asked to show my identification a half a dozen times! In the confusion of removing clothing and opening bags for inspection, I misplaced my ID several times. Was it in my pocket or my wallet or at the bottom of my purse? I would panic until I laid my hands on it.
My advice is to cover the ID in plastic and hang it around your neck, the way some kids hang their bus passes. That way you can flash it as needed and know where it is at all times.