PSP charger is 100-240V and 50-60 Hz compatible. You'll need the proper prong adapter or cable, but I'd recommend waiting until you get there and buying a normal device cable at like Woolworth's. It's one of those normal 2 pin cables like you use to hook up a home amplifier, Xbox, Ps2, Dreamcast, etc.
For the plane ride, I'd recommend building a battery box (if you're electronically adpet). PSP takes 5V @ 2A as input, so 4 D cells (NiMH) in series with a 2.4 ohm resistor will provide the correct output and give you ~44,000 mAh of power, the equivelant of 22 hours of power (in addition to the built-in battery).
Downsides: Between the batteries and case, you're looking at roughly $50 in parts. Upside, it's just a little more expensive than a PSP battery, and you can always cut the end off and use it for something else (digicam, PocketPC, cell phone, etc). Nice thing about using standard parts.
