The Original Hot Dog Shop, known to those who frequent it as "The O", is truly a Pittsburgh landmark. It has two locations, one on Forbes Avenue near the University of Pittsburgh and one at the university center at Carnegie Mellon University. Aside from being a popular hangout for college students, The O has several distinguishing characteristics.

First and foremost among these is the quantity of french fries that comes with each order. A small order of fries is slightly larger than the amount of fries that you would get in a large fry at McDonald's. A large fry covers an entire cafeteria tray and can easily feed 3 football players or 8 college students. Fries come with tubs of ketchup, but for a small additional cost, you can also get mustard, cheese, mayonnaise, or gravy.

The O by University of Pittsburgh is the main location, and is open later than any other eatery in the area. On weeknights, the Original Hot Dog Shop stays open until 4 am, and on weekends until 5 am. However, this late-night convenience does not come without a price. The O is frequently the site of crime, and it is a rare night when you can drive past the O without seeing three or four police cars parked outside. To pay for this security, there is a "late-night security surcharge" after midnight.

The O was opened in 1960 by Sidney Simon, and will probably continue to be a Pittsburgh tradition for as long as there are college students looking for cheap, greasy food available at any time.