Apple has announced
the USB Power Adapter Takeback Program. Apple says, "Recent reports have suggested that some counterfeit and third party adapters may not be designed properly and could result in safety issues. While not all third party adapters have an issue, we are announcing a USB Power Adapter Takeback Program to enable customers to acquire properly designed adapters."
Apple says it will let customers purchase one Apple USB power adapter at a the price $10 USD, or approximate equivalent in local currency, for a limited time. To qualify for the discount, you have to turn in at least one USB power adapter and bring your iPhone, iPad, or iPod to an Apple Retail Store or participating Apple Authorized Service Provider for serial number validation. The special pricing is valid until October 18, 2013.
The Apple 5W USB Power Adapter for the iPhone 4, iPhone 4S, iPhone 5 and iPad mini is pictured above and the 12W USB Power Adapter for the iPad with Retina display is pictured below. You can information about Apple adpaters here