Watch out, Nook: Amazon has just launched a 3G version of its ad-supported Kindle for $164.

The new device, officially called the Kindle 3G With Special Offers, is almost identical to the $114 ad-supported Wi-Fi Kindle except for the addition of 3G functionality. The device is a 6-inch device that displays the occasional advertisement. In return, users get special offers and a $25 discount on the Kindle 3G’s $189 price tag. In a statement, Amazon Kindle director Jay Marine called it “the lowest price for any 3G ereader.”

The special deals associated with the 3G Kindle are similar to the Wi-Fi version. Some of the special offers Amazon will launch “in the coming weeks” include $10 for a $20 Amazon gift card, 20% discounts on 200 HDTVs, and $1 for select Kindle books.

The announcement of the Kindle 3G With Special Offers comes just hours after Barnes & Noble unveiled its $139 touchscreen Nook, a Wi-Fi-only ereader device that is lighter than the Kindle and boasts two months of battery life. Barnes & Noble also claims that it controls 25% of the ebook market, something that can’t be sitting well with Amazon.