Barnes and Noble's rumored dual-screen e-book reader gained credibility Monday night with the leak of a paper ad in advance (subscription required). A full-page placement due for the New York Times' Book Review next Sunday labels the reader as the Nook and says it will ship for $259, reaching the same price as the US Kindle. It also makes a direct reference to the previously leaked e-book lending feature, which would let users temporarily give rights to a book to someone else.

Other features known by the Wall Street Journal to have been mentioned so far are those that have previously surfaced, including built-in Internet access and the use of a color touchscreen for the interface as well as a grayscale e-paper display for actual reading. It's still unconfirmed whether the reader will have 3G, Wi-Fi, or both, though at least one will be necessary for the expected option of downloading books directly from Barnes & Noble's own online store.

The pricing if true would put severe pressure not only on Amazon but on iRex and eventually Plastic Logic, both of whom plan to bring 3G-aware e-book readers to the US within the next few months. No mainstream e-book reader to date has had a secondary touch display, and current devices with button-only controls have only recently broken below the $300 mark on a wider basis; rivals to Barnes & Noble's design are few and at most include the Spring Design Alex, which has yet to obtain a hardware manufacturer and more concrete details.