OpenTable is an online reservation service. It lets people find reservations at local restaurants and book them from their computer or mobile phone; all the while, not having to use the traditional system of calling or visiting the restaurants in person. The service is currently available in all 50 states (big cities, for the most part) as well as a growing number of international locations. Total number of restaurants is now in the tens of thousands.
OpenTable's reservation system allows customers to search for restaurants on three different criteria: type of cuisine, restaurant name, or location/neighborhood. Customers can make reservations months in advance or find out whether there are tables open the same night. As part of the system, the company sets up a terminal in each restaurant that can be used to input phone reservations as well. Reservations made online come in through the Internet and show up alongside other reservations.
Along with its reservation system, OpenTable also maintains a database of restaurant information and reviews from both its users and partners. Similar to Yelp and CitySearch, this lets people recommend or discourage restaurants in OpenTable's database. Those reviews show up to other users when they do a search or while they plan to book a reservation.