Google Notebook was very promising. I prepared pages of instructions for learning to use it, and enthusiastically taught numerous groups of teachers how to do so. And then, a bit more than a year ago, Google decided to phase it out. A few months ago, when I noticed some changes that were moving Bookmarks in the direction of Notebook I started preparing new instructional materials, only to discover that only after a couple of weeks these changes disappeared and that Google was apparently cooking up something else. It seems that things are in a state of flux - which is probably always the case, but even more so today. If I want to teach this particular tool it seems that it's worth waiting until things stabilize a bit more.