What's your sign?
Gemini, the creature with two heads. Essentially for those people with two sides to themselves, one for the inside and one for the outside. This is (or used to be, anyway), a common introduction in American culture. "Hey baby, what's your sign?"
In Japan, surprisingly, a more common question is "what's your blood type?" I kid not. How ridiculous. How could the Japanese believe that a person's blood type can determine his personality, when it's a well-known fact that the positions of certain stars determine our future? In case you're wondering, if sarcasm were strawberries, I'd be eating a pretty big smoothie right about now. Blood type seems more "reasonable" to me than astrology.
The anal-retentives. Hard workers, OCD, but usually of strong moral fiber and trustworthy. Superman.
The curious types. Moving from subject to subject, they tend not to have a strong hold on anything or anyone. Very imaginative. Will Farrell playing Harry Carey, definitely.
The sensitive ones, who tend to be the blood-equivalent of The Gemini. Two sides to themselves, definitely more introverted than extroverted.
The fun-loving, happy-go-lucky crowd. Most flexible, least dependable. Think of Will Farrell in Old School.