A chain of fast food establishments, the East Coast (or perhaps just the Baltimore-Washington corridor) equivalent of White Castle. One key difference: there's only one Little Tavern left in existence. Drive south down U.S. Route 1 in Maryland through Laurel, and it's on your right about half a block past Main Street.
Their slogan is "Buy 'em by the bag". Indeed, you can't get a single burger; the little square concoctions (distinguishable from White Castle sliders by the lack of five holes) are available in multiples of three. No fries are available, as there's hardly room inside the building for more than 6 people, much less a deep fryer, but you can get potato or onion chips with your sack of burgers. Breakfast is also available, though it's only recommended as a hangover cure.
It's not a place you'd take anyone you're trying to impress. But if you've had them (or White Castles) even once, every once in a great while, you just have to get yourself a dozen of the little GI tract wreckers and say to hell with the consequences. Frozen White Castles just don't cut it at those times. I'd hardly call a half-ounce of ground beef, steam-grilled on a dinner roll with rehydrated onion flakes and a tiny pickle chip (cheese optional) comfort food, but there's some mysterious quality about the things that calls to you at least once or twice a year, and the craving can't be satisfied any other way.