made available today a new edition of the Kindle 3G, one day after Barnes & Noble Inc unveiled the latest installment of its Nook e-reader.

But Amazon's announcement provides little more than a price drop, as the new Kindle 3G is priced at $164 in exchange for advertisments placed on the home screen and screen saver. Amazon did the same for its Kindle Wi-Fi, dropping its price to $114. The e-readers are normally $189 and $139, respectively.

The new Barnes & Noble Nook will be available for shipping June 10 for $139.