Steven Poole’s book Trigger Happy was one of the first books giving a history and aesthetics of videogames – and it’s very accessibly written too. We’ve used it successfully in teaching a couple of times at humanistic informatics. Now he’s offering a free (as in free beer) PDF of the British, 2000-edition of the book, under a Creative Commons license – for a limited, though unspecified, period.
I’ve asked our library to see whether the library can legally archive a copy so that readers can access the book digitally even after Poole removes the file from his server. The paper edition of the book’s currently on loan at about half the Norwegian libraries that own a copy, so it’s clearly popular.
CC licenses are perpetual and irrevocable. So if you download it now, under the terms of the license you can redistribute the original work (though not a derivative work, based on the license he’s chosen) indefinitely.
See section 3 and 4 of http://creativecommons.org/licenses/by-nc-nd/3.0/legalcode for details.