The first time I head about this personality classification was a month or so ago when my wife Adriana met some human resource consultans that were working on her office. They took everybody in her office these and other tests and back at home, she tough me about it. My sister is a psychologist, one of my best friends of all life (sorry for not communicating very often with you, Ricardo) is a psychologist. I have been myself in therapy (for a short period of time, a long time ago, and I've never been crazy, ok I am not anymore, I swear ;) and I have read some texts that I would consider very "technical" in psychology. So, when I heard of this "too simplistic" classification I was completely suspicious of it. But after we arrived to the conclusion of what personality type I was, Adriana began to read some of the common characteristics of NTs. This one made me fall on my knees laughing: "When somebody express admiration for something you do routinely, you immediately get suspicious of his/her hidden agenda" (more or less). The descriptions went on and on, and we had a lot of fun. Of course I think there is a lot more in a personality than I, E, N, S, T, F, P, J, and I have seen some material online that looks too much like horoscopes based on the personality types. But I still think there is a lot of value in this classification. At least, since I learned I am an INTP I have discovered some things about my personal needs that seemed to be buried under meters and meters of extroversion disguise. Adriana and me have found our son to be introverted too and that has helped us a lot to set up the self-confirmation that he wasn't receiving from his extroverted teachers at the nursery school.
Next time I heard about it was next week in one (or many) of the .NET bloggers I usually read. They seemed to found about it almost at the same as me. And they found many of them to be ENTJs, which is supposedly also Bill Gates type. One of them suggested Microsoft should replace their current lengthily interview process with only the personality type. So if you are ENTJ, you can be a Microsoft employee. What a disappointment! ;)