Pop Burger   

File this one under 'Meatpacking District Gentrification Blitz.' On a block formerly distinguished only by the longstanding Old Homestead steakhouse, restaurateur Roy Liebenthal (of the extremely chic Pop, near Union Square) has staked a new claim in the city's upscale-burger trade. But with its brightly lit aluminum counter and no-nonsense tables, the front section of Pop Burger actually resembles a fast-food joint of the healthy California variety. Burgers are roughly bite-sized and come in pairs, cooked to order and topped with the usual fixings. The less carnivorous can opt instead for a grilled chicken sandwich, a Portobello 'invisible' burger or a very tasty mixed-greens salad, all reasonably priced. As for the see-and-be-seen factor, Liebenthal has covered those bases with a sequestered restaurant-lounge in the rear (pictured), designed by Ali Tayar and boasting a pool hall, banquettes, its own finger-food menu, and yes, a guest list. The spot's duality is an ingenious move: Anyone turned away from the lounge can find easy consolation up front, in the form of a thick milk shake and crispy fries. -- Nate Chinen