It's helpful, but I would prefer a different organization to make it a little less overwhelming. For example (in addition to the dictionary format), a shampoo section with the list of animal products which one is likely to find in shampoo. It would make the book thicker, but a bit more practical for shopping purposes. But it (or something like it) is a must have for vegans. I've heard you can buy the book for your ipod; maybe it's a little easier to use that way.
Plus, in the beginning of the book, there is something said about fruit being coated in something similar to geletin (thus animal), and I was bugged by the offered solution: peel the fruit before eating it. Really? What the hell good does that do? If you buy it, the damage has been done!