When we saw someone on St. Marks Place holding this cup, we said “hot diggity damn” — Gold Coast Dogs? Our favorite place in Chicago for grilled hot dogs topped with celery salt, pickles, peppers, and always mustard (their T-shirt is a bottle of ketchup with an international “No” sign)? Could it be that the Gray’s Papaya of the Midwest had come to these parts? We asked the person holding the cup — maybe frightening her a little bit — and she told us she got it from around the corner, at St. Marks and Third Avenue, where we found… Ray’s Pizza? It turns out the pizza joint bought some surplus Gold Coast cups from a wholesaler (the cups advertise an outdated Website — goldcoastdogs.net), and is using them for fountain soda. Sigh. You’ll still have to wait it out at the Shake Shack for a Chicago-style hot dog, but in the meantime, if you want a souvenir, there’s a stack of cups where this came from.