Excellent, I'll look into getting a copy of that. I have several of his other books (GEB, I Am A Strange Loop, Metamagical Themas, etc.) but only got about 1/3rd of the way through GEB before setting it aside to focus on other stuff for "a while". Unfortunately "a while" has turned into over a year now, so I guess it's time to get back to it. :-)
Fluid Concepts & Creative Analogies ch 4-6 are the best introduction to his modeling work. I can't recommend them highly enough.