Cupholder Power Adaptor/Charger
The Cupholder Power Adaptor and Charger measures 2.5" x 3", weighs 6oz, sits in your car's cupholder, and charges things through the cigarette lighter. There are two USB slots and two DC slots, the latter presumably those who already have single-cord adapters for their individual devices. It even has a power-indicator LED light to keep track of power consumption. Simplicity itself. It's available for $19.85 from Magellan's.