This article is a pretty good nontechnical discussion of the costs of producing an ereader. From the NY Times:
With ereaders like Apple’s new iPad and Amazon’s Kindle touting their vast libraries of digital titles, some bookworms are bound to wonder if tomes-on-paper will one day become quaint relics. But the question also arises, which is more environmentally friendly: an ereader or an old-fashioned book?
To find the answer, we turned to life-cycle assessment, which evaluates the ecological impact of any product, at every stage of its existence, from the first tree cut down for paper to the day that hardcover decomposes in the dump. With this method, we can determine the greenest way to read.
(A note about ereaders: some technical details — for instance, how those special screens are manufactured — are not publicly available and these products vary in their exact composition. We’ve based our estimates on a composite derived from available information. It’s also important to keep in mind that we’re focusing on the ereader aspect of these devices, not any other functions they may offer.)