What's greener: e-readers or books?

Interesting op-ed comparing the lives of ereaders and physical books, from the materials used to make and manufacture, transport, read and dispose of each item. The author calculates where the environmental break even point is - and of course mentions the most eco-friendly option: your library!

http://greeninc.blogs.nytimes.com/2009/08/31/are-e-readers-greener-than-books/