Twice a year New York City's many diverse restaurants participate in a marketing exercise called Restaurant Week which enables you to experience their fare at a fraction of their price. Winter Restaurant Week is usually held in January while summer restaurant week is held in what are considered 'slow' months for New York City restaurant scene at end of July or early August when many New Yorkers flee the oppressive heat in the city for beach locales like the Hamptons. 
However this is the time that New York City is inundated with tourists and if you are planning to visit New York City over the next two weeks it would be wise to check out the list of participating restaurants of Restaurant week so you can get to eat at famous New York City restaurants like the cavernous Del Posto, or high end celebrated Japanese restaurants like Nobu and Megu for a fraction of the price that they normally charge.
This year restaurant week is to be held over two weeks on week days only from Monday July 21st to Friday July 25th and from Monday July 28th to Friday August 1st. The Restaurant week menu at participating restaurants is not offered on weekends. During Restaurant week this year participating restaurants will offer a three course lunch menu for $24.07 while a similar dinner prix-fixe will be available for $35. Some restaurants offer Restaurant week menus for both lunch and dinner while some only offer lunch like renowned chef Mario Batali's Lupa Osteria Romana located in Greenwich Village or dinner like the stylish Mexican restaurant Maya which is located on the Upper East Side.
This prix-fixe restaurant week menu does not include beverages, gratuities or taxes but even then many local New Yorkers and tourists wait for Restaurant week in order to visit the many hip restaurants that dot New York City's restaurant landscape at a time that they are relatively affordable. So it is best to reserve early during Restaurant week when popular restaurants may be fully booked up. Reservations for Restaurant week can be made through the website of Nycvisit or Opentable.com
Being a foodie, I fully intend to take advantage of Summer Restaurant Week to visit some of my favorite New York City Restaurants like:-
Quality Meats at Midtown West
Located in a building that once housed the Manhattan Ocean Club, Quality Meats is a raucous restaurant which has a definite masculine vibe but serves excellent steaks and delectable ice creams.
Amma at Midtown East
Anju Sharma's small and cozy restaurant serves the 'best' Indian food in New York City.
Dos Caminos (three locations at Midtown East, Park Avenue South and Soho)
Dos Caminos at Midtown East was my choice for Winter Restaurant Week when I had friends from overseas visiting. The Dos Caminos restaurants are part of the B.R. Guest group of restaurants and serve great Mexican food in a lively atmosphere. Try their excellent Prickly Pear Margaritas as a respite from the summer heat.
Chinatown Brasserie, Soho
I love all kinds of Oriental cuisine but haven’t had a chance to sample Chinatown Brasserie's fare. I look forward to doing so during Summer Restaurant Week.
Images were from http://www.flickr.com by Panduh, Cormac70, Phil Thomas and cresny.