I believe it's available only as a subscription to an e-publication for one year.

Personally, I would pay a little bit more to have a hard copy, or at least a permanent download. Ah well. Anyway, if you look down at the bottom of the page there is a little icon that looks like a calculator. If you click on that you can buy a password to read the book. It's not very well marked. I actually know his web designer. (Well, his web designer's wife, anyway.) I should give her a hard time about that. >

But, as I haven't actually come out yet, I guess I'll let it be for now.