I am the same way Diane, I usually bring a minimum of two books on a trip. It really does help pass the time on a plane.
I can't wait to be leaving on our next trip! Couple more months to go!

I suspect running a GPS receiver is against the rules, and unless you were at a window you'd unlikely get any signals anyway and even at a window the data would be of dubious quality (geometry).
Other than that, it's the usual routine of sleep, read, crosswords in inflight mag, have a Tanqueray or two (the real "green flash" according to wizard pub books), drink water(BYO) and (perhaps)eat the "food" offered or BYO (DFW has a Subway close to the gate). I stay up late the night before so I'm more inclined to sleep during the day's run to the islands (7-8 hrs from where I live, mid-morning departures). American doesn't encourage too much moving around, especially gathering down back (can't blame them). Personally I never rent headsets...
Have a wonderful trip, Gil.
Cheers

10 thousand bottles of beers on the wall.....

I find heavy drinking to be a nice time-passer. Here's a tip for you... I'm a beer drinker, and given the fact that the FAs only come around every so often and that they have the beers in their carts the whole time, getting warm, on a super long flight I order all my beers in advance. For a mainland to Hawaii flight, I would order three... one on the tray to drink immediately, and I ask the FA's to put the other two in a barf bag, and ask them to fill the rest of the bag with ice. Put the bag in the seatback pouch in front of you, and by the time you are ready for them, they will be ice cold. After you drink the three, take a nap, you'll be there.

Watch the movies, bring some crossword puzzles - if you like doing them they are a great way to pass the time - and bring a book. I find having a few different things to occupy me makes it pass even easier.

The absolute best way to survive a long flight is to fly first or business class. Much easier on the old body and better food.

One other thing, once you done a really long flight, ie, to Australia, the 8 hour flights to Europe or Hawaii are much easier.

I don't think anyone has mentioned eyeshades if you want to sleep. Our last overnight return flight on American was in a plane that had individual screens in the seat backs for the movie. I was comfortable with my inflatable horseshoe neck pillow, but all the flickering light from the screens kept me awake. Next time I'll take an eyeshade too.

I had to laugh, when someone mentioned that compared to other long flights, the flight to Hawaii was a snap. My wife and I were just talking about it. We are leaving from South Florida so it is an all day adventure for us. But, considering the flights we have taken to India, China or back from Singapore (real long) to South Florida, this would qualify for just one leg of the trip.

But, it is still a long flight. I usually just get in the "travel mode" knowing what I will be doing I kind of psych myself up for it. I know I'll be cooped up for hours upon hours, seems to makes it easier.

Bring your own headphones. We have many from the different airlines. They have never complained when I brought my own. OK, so saving $10 on a trip to Hawaii is not that much, but I like a deal as well as anyone :~)

I read, watch the movie, get up, etc. Take plenty of snacks. My wife usually sleeps. I will sleep on the red eye back, but not going over.

Have a great trip.
Duane