Having grown up around the 'burgh, I wasn't aware that the rest of the country had long been deprived of chipped ham sammitches. When I went away to school and tried to buy chipped ham, the deli was thoroughly confused. Apparently, chipped ham is a Pittsburgh treat.

"Chipped Ham, a spicy lunch meat, made its debut in 1933 at Isaly's, a locally based family chain of dairy stores. Former Pittsburghers have been known to have it shipped across the country when they get a yearning for this hometown favorite."

Source: http://www.majestytransportation.com/pittsburghfacts.htm