It's rare that I'm on a flight that isn't completely full. It's even rarer that I'm on a flight that is nearly empty. This 737 from Boston to Phoenix has about a couple dozen passengers. Most of the overhead bins are empty. Kathryn and I have spread out to a window and aisle seat.
Although I usually bring a computer with me when I travel, I generally don't use it when I'm on an airplane. I value my privacy. I prefer to pull out a paper notebook and a pen and write in cursive. Even someone sitting next to me would have to strain to decipher that.