I always carry my sketchbook with me and love to pull it out to help pass the time.
When my kids were younger, I did a lot of waiting. There were the weekly activities like piano lessons and soccer practices so I'd find myself with time to kill.
Now that my kids are grown, I don't sketch nearly as much. This past weekend, I was traveling and, once again, found some quiet time to pull out my sketchbook and happily passed the time waiting for my plane to depart.