I wouldn't know about pizza orientation, but here in Brazil, (some) folk from São Paulo can be recognized for pouring a little olive oil on their pizza, whereas (some) Rio de Janeiro folk can be recognized for seasoning their pizza with ketchup.

(Folk from Minas Gerais are said to sometimes dip their cheesebread loafs in their coffee; those coming from the West drink their mate cold, from a horn called guampa, and call it tereré, whereas folk from the South drink it hot, from a bowl called cuia, and call it chimarrão.)

Though a bit proverbial, those are all region-specific and common enough that they can be thought of as "reliable enough" as a conversation starter.