I have been thinking about Extreme Programming and Bazaar style development. It seems to me that both are development models for extraverts - people who get energy from being with other people. Extraverts like to think out loud, i.e., the bazaar. Introverts prefer to work it all out privately before presenting publically, i.e., the cathedral. I have done some of the two person, one terminal work for debugging sysadmin problems. We called it "getting the intersection of our blindspots". It is effective, intense, and draining. I think three hours a day is about I could stand without wearing out. I'm not terribly introverted as programmers go, so I wonder how this works for the general programmer population. With the adoption of these two models, I expect to see more extraverts in programming.