In the east we use mustard on our dogs...in Texas they use ketchup more...in San Francisco they use mustard...they have to because Dirty Harry says so...
"We'll let Dirty Harry makes the point. In the film "Sudden Impact", Clint Eastwood, playing detective Harry Callahan, a.k.a. Dirty Harry, appearing at a crime scene, blows his top while watching a cop munching on a hot dog: "Nah, this stuff isn't getting to me, the shootings, the knifings, the beatings, old ladies being bashed in the head for their social security checks. Nah, that doesn't bother me. But you know what does bother me? You know what makes me really sick to my stomach? It's watching you stuff your face with those hotdogs. Nobody, I mean nobody puts ketchup on a hot dog."