Free draft: http://www.cs.cmu.edu/~rwh/plbook/book.pdf
(Get it while you can... Publishers often require authors to take down drafts once the book is published.)
(Get it while you can... Publishers often require authors to take down drafts once the book is published.)
This book is published by Cambridge University Press who have a good track record for allowing electronic copies to stay up [1]. It will be interesting to see how they adapt as e-readers become a compelling alternative to hard-copy for this type of text of book. I'm afraid I won't like the answer.
[1] Examples: http://www.stanford.edu/~boyd/cvxbook/ http://www.inference.phy.cam.ac.uk/mackay/itila/book.html