I'd say this would fit in nicely with the whole Moleskine resurgence:
But perhaps the pendulum will swing back towards pocket editions again. HarperPerennial recently introduced the Olive Editions collection. According to the marketing material, "they fit in your back pocket and only cost ten bucks each." (And eight bucks on Amazon). So far the line includes three titles, The Mysteries of Pittsburgh by Michael Chabon, The Unbearable Lightness of Being by Milan Kundera, and Everything Is Illuminated by Jonathan Safran Foer. At 7 inches by 4 1/2 inches, they are a touch larger than the pocket paperbacks you see in used bookstores, and while their cover design is smart looking, they are not as inviting as the pulpy art that used to emblazon even the classics. Nonetheless, they represent a smart move by HarperCollins, and one hopes that they will announce more titles in this format and that other publishers will follow suit.
A full-fledged return of pocket paperbacks would be surprising, however, as ultimately it seems likely that an even smaller format will take center stage, a format that is indeed infinitesimal. With hardware innovations driven by Amazon's Kindle and perhaps Apple and Sony as well, reading on these devices will become more palatable for a larger percentage of readers. Selection of titles will improve and developments like Google's recent deal with publishers will further expand the availability of titles in digital formats.