Behold, my cache of travel devices. Let me accede, up front, that I'm a nerd. If your traveling circus of electronic contrivances is grander, then you're a better nerd than I. We (that is, I) say that all this stuff is necessary. Starting with a good power adapter/converter. See the gray 110-220v power adapter in picture 1, below. It's a big, HEAVY chunck of metal. I don't know of any alternative. Notice the 2 pins coming out of it at the top. That's what every plug there must look like. The pins are slightly less thick than chopsticks. So half the time they slip out of the corrosponding 2 holes in wall sockets! Note my solution-by-tape.
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 (as they are in the US), 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.