I received this book last week Monday. When I bought this book, I was very sceptical about this book because a peacock on wheels on the cover was a little strange. But I also build a Giraffe with a fifth middle leg based on the book from Benjamin Erwin "Creative Projects with Lego Mindstorms (RIS kit)" which seems also unusual at that time. Also the book of Benjamin Erwin is also an excellent book. So this is of no surprise that I bought this book also.
My skepticism melted as snow for the sun when I saw the creatures and the building instructions inside the book. This book is clearly written with its audience in mind, ie Children. The building instructions are very clear and detailled. The explanations are also easy to follow.
What could be improved, is the explanation of the NXT-G programming language. In my opinion they go not deep enough. An in depth coverage of the NXT motors, touch, ultrasonic, light sensors is missing. Expecially the "Why" and "What for" questions are not answered. But that is already written in Jim Kelly's book "Lego Mindstorms NXT-G Programming Guide". Both books are complementary to each other. So if you buy the NXT Zoo, I think it is a good idea to by the NXT-G programming language also.
I build "Spiderbot" without any problem (I am an adult, I love robotics and bought my first RIS set in august 2005). I found it easy to build, despite the fact those images are not in color. Using color should have added an extra "touch" to this fine book but it would make it also much more expensive. Nevertheless all those images give a very clear and detailled view how to construct the animals.
Also the detailled inventory at the beginning of each design and the part substitution prevent of becoming frustrating when you need a piece of which you just ran out or do no have. You can clearly see what pieces you need and how much before you start building. When you have already bought other Lego Technic sets, you probably will have all the pieces you need. Only the canon seems to be a big problem because this piece seems very hard to find (I am living in Belgium and probably therefore I cannot find a place where I can buy the particular set). But when you live in the USA, there should be no problem at all. Also there are other types of Lego cannons (in the Excoforce sets) which can be substitution for this canon but I did not try it yet.
What I really regret about this book is that it is written in English only. So when your native language is English, your child can start building without problems. But when you like me living in a world with a different language (mine is Dutch), it makes it almost impossible for your child to follow the instructions on its own. I decided to translate the book into my Dutch language for my nephew and when it is allowed by the publisher of this book, I am more than willing to share the Dutch translation with others inside the Lego community. But I think because of copyright matters that this is not allowed. Nevertheless I can understand the reason why it is impossible to produce such books for other languages; English is a main language used in almost every part of the world. When this book should be written in Dutch for example, theya are only selling less than thousand copies because our language and many others are rarely used and only in very small parts of the world.
As my final conclusion. This book is a must have for children with in interest in animals and robotics. In a playfull way, they obtain technic insights and improve their skills. Also this book stimulates creativity because while building you get your own ideas on what could be added. On Spiderbot I would add a second "Ultrasonic" sensor pointed to the ground. So when Spiderbot is on a table, it should detect the end of the table and backup and start walking on another angle. Nevertheless when you add a second Ultrasonic sensor, you have to make sure you are using those Ultrasonic sensor in an intermitting frequency (the front off when your program is using the floor sensor and so fort) otherwise you do not get excact results. If an ultrasonic sensor is too difficult, you can use a light or Hi-Technic color sensor to scan the surface Spiderbot is walking. When the surface changes color, spiderbot backoff. For this kind of approach, your spiderbot can walk only on egally colored surfaces. And when you add a Compass sensor ... You see a lot of extra creativity can add a personal touch to these designs.
So lets start building and experimenting. This book is worth the price which is very reasonable in my opinion.
And about the author Fay Rhodes, very good work indeed! If we had an "intergalactic" Lego Hall of Fame you would have definatelly "First place". Hopefully we will see much more of your work in the future. Also a big "thank you" for your work inside the Lego Community.