Bestek 400W AC Inverter
If you're a true road warrior, you'll want something like this little gadget.
For a low price, Bestek will let you invert power from your car into two AC outlets for gaming consoles, laptops, or anything else for that matter. It's basically a way to get two plugs in the car like you have on the wall at home.
Take it on a road trip and you're all set. Charge four devices with the USB ports, then connect up to two laptops or other devices to the AC outlets and keep the entire family entertained for hours.