This is a really smart idea — a dual port charger! This device will actually allow you to charge two devices from a single port. Here is the product description, so you can learn more:
The Vaas Mobile dual-port USB charger plugs into the power port in your car to keep your devices powered up and ready to go when you’re on the road. Vaas Mobile’s dual port USB car charger is a compact and sleek charger that hardly takes up any space at all. With its dual USB power output you can even charge two devices at once. Choose from the low powered 1 AMP USB port for charging device like your iPhone, Blackberry, GPS or other small mobile device.
Use the high powered 2 AMP USB charger to rapidly charge your larger device (i.e. Apple iPad, Samsung Galaxy Tab, Nexus 7 etc.) The charger is compatible with virtually all electronic devices; as long as you have the original charging cable that came with other devices (Apple 30-pin, Micro USB, Mini USB), you can charge these as well. The dual-port USB charger also features an internal IC chip that controls the charging circuit, which means you won’t be replacing any fuses. Make the smart choice and get the power your devices crave with the Vaas Dual Port Universal USB Car Charger.