Tanga offers the Lenmar Dual USB 4.2A Car Charger, model no. AIDCU4, for $4.99 plus $2.99 shipping. That's tied with last month's mention and the lowest total price we could find by $2. It's equipped with a fuse to protect from overcharging, and both ports have 2.1A of power (most duals have 1 port at 2.1A and the other at only 1.4A). This lets you charge two tablet devices at once.