Okay so I'm facing a long ass flight to Asia. I wanted to catch up on photoshop stuff and maybe watch a movie or two. I have the 13" macbook and I know it's not going to last that long. Planes don't usually let passengers hook up their computers to the outlets. Aside from an extra battery, know of any 3rd party batteries that would work with the macbook? (I know Energizer has one for portable DVD players but I doubt it will be compatible with the notebook).