Ask, "What high school did you go to?"

No matter what the answer, sound like you know the place and ask about a fellow student. "Oh, yeah. Did you know Sunil Vanaswammy?" If you can't place the accent or can't think of a name quickly enough to match it, use Gary Johnson (unless that's your name, in which case use Bill Jones or Brenda Smith). Then start talking about this fake person.