UPDATE 11/3/13: All the new 2013 Kindle Fire HD and Fire HDX's come with their own charger so you won't need to buy one of these separately for those devices.
UPDATE 10/15/13: This will work to charge any of the 2011/2012/2013 Kindle e-Readers: Kindle, Kindle Keyboard, Touch, Paperwhite using the included USB cable that it comes with the e-reader. In fact, it is what I am also using to charge my 2012 Fire HD although the Fire would charge faster with the newer Amazon Kindle 9W PowerFast Adapter for Accelerated Charging
The newer Kindle e-readers(Kindle, Kindle Touch, Kindle Paperwhite) come with an included USB 2.0 USB to Micro-B cable that you can use to charge your device by connecting it to the USB port of a computer. But the specs also say:
"U.S. POWER ADAPTER SOLD SEPARATELY"
So you are going to need one of these if you ordered one of these Kindles and want to wall charge it. For awhile these were 50% off as Amazon was trying to take some of the sting out of the deal for when everyone finds out that they need an adapter to plug/charge it in a wall outlet. In the past(before 2012) all Kindles came with the adapter included in the purchase price. Welcome to the new Amazon! A plus, however, is that it will also charge any iPod that charges via USB.
This is the same adapter that you should already have if you own one of the the first generation Kindles, so no need to buy a 2nd one. I lost the adapter on my Kindle 3(Kindle Keyboard) and had to buy one of these.
It's a nice, small adapter with an Amazon logo. It does exactly what it is designed to do, charges a Kindle. Do yourself a favor. If you need one, buy it directly from Amazon or from a seller with a "Fulfilled by Amazon" designation so you qualify for the the 30 day hassle free return/replacement policy.