check this out! http://foursquare.com
What is foursquare? All about helping you find new ways to explore the city. Foursquare help you meet up with your friends and let you earn points and unlock badges for discovering new places, doing new things and meeting new people.[Learn more!]
If you own a bar or restaurant, foursquare can help you find new ways to connect with your customers. If you're a developer, check out the foursquare API.
