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  Yelp

  San Francisco User Reviews and Recommendations of Top Restaurants, Shopping, Nightlife, Entertainment, Services and More at Yelp
  http://www.yelp.com

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  Tripadvisor

  World's Largest Travel Site. 200 million+ unbiased traveler reviews. Search 200+ sites to find the best hotel prices.
  http://www.tripadvisor.com

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  Foursquare

  Foursquare helps you find the perfect places to go with friends. Discover the best food, nightlife, and entertainment in your area.
  http://www.foursquare.com