Salesman Syndrome

Last year I read an interesting article in Wired about Aspergers Syndrome. It is a milder relative of autism, characterized by poor social skills and an obsession with one subject, to the exclusion of all else. It is a serious problem, but some people have a mild undiagnosed form. My son is not one of these, but he is in an advanced high school program called the International Baccalaureate Program. I asked him if any of his classmates had very poor social skills but an obsessive knowledge of one particular topic, and he immediately thought of three people. For example, one can tell you everything about airplanes, all airplanes since they were invented.
In the past, these people might have become your weird uncle who lives alone but can tell you everything about stamps. Today they might be your weird uncle who is a programmer for Google, and codes without a reference book. And he is quite wealthy.
Consider that this seems to be a range of behavior, and some people are just too far along the scale to function, while others are just nerdy. The stereotypical nerd is a guy with poor fashion sense, no friends, lives with his parents, and knows everything about computers.
Another characteristic is the ability to work in a system of rules. Some people with Aspergers have been trained in social skills. Just teach them the rules they don't know intuitively, and they can pass for normal.
What is at the other end of the range? People who can read people, but can't follow procedures, can't deal with details. Salesmen. I have more trouble with salesmen than anyone else. They forget passwords, they forget how to get connected. So maybe they have the opposite of Asperger's, and maybe some extreme cases are those people with genuine charisma.