Been fighting over the single USB charging cable in your car? This deal will alleviate all your car-charging-related problems. Amazon has a PowerGen Dual-USB charger for only $7.99, and it's rated at 4.6 stars.
This charger outputs 3.1A across the two USB plugs, which is enough to supply power to two thirsty devices at once. One of the ports is supposed to be for Apple devices, and the other for non-Apple.