Behold, my cache of travel devices. I claim all this stuff is necessary.
The first thing you must think about is electrical power. The electrical standard in Tahiti, French Polynesia is 220 volts and 60 hertz (Hz) alternating current (AC). North America and parts of South America use 110V. If most of your appliances plug into a 110V socket, you will need a GOOD power adapter. Some laptops are switchable between 110 and 220. Look at the gray 110-220v power adapter in picture 1, below. It's a big, HEAVY chunck of metal. There is no alternative. Notice the 2 round pins coming out of it at the top. They plug into a wall. That's what every plug there must look like. But the pins are usually too small, and easily slip out of the corrosponding 2 holes in the wall socket! Note my solution by tape, which itself is also a necessary item.
Look at the 2 setups I have in pics 2 and 3. I have to have the white and gray adapter anvil hanging off the wall by its 2 pins, and off of must hang the power supply for our laptop (anvil #2.) This setup always seemed to necessarily end up in the worst configuration possible: maximum stick-out-of-wall-ness. If you're appliances are based on the 110 volt standard, you will need one where ever you stay in Tahiti or Bora Bora, where their electrical standard is 220V.
Mind you, I liked this adapter itself. It was just all the infrastructural delivery aparatus that brought me down, man. The cords, plugs, sockets, outlets, pins, etc, seemed amateurish. But this adapter was a lot better than the first one I bought there, which was twice as heavy as the good one (See "crappy, locally-bought adapter.") We were really lucky to find the 2nd one, which I got it at Carrefor super store.
For us, a USB fan is very useful. We both tend to get hot on a long flight, and those ceiling fans aren't enough. You can plug it into the usb port in front of your seat. Never bring any battery-powered appliance on a trip if you don't have to.
Note, don't forget to pack all the LITTLE THINGS. For me/us, these are: extra iPhone chargers/cables, scotch tape, rubber tape, a small stapler, gummed labels, extra zip lock bags, a lighter, and extra batteries for all your electronic gadgets. Naturally, I'd forgotten to pack half of these things. Thank you, Carrefour.