Foursquare is a very hot social networking tool that posts updates to users friends about where they are. It also incorporates a game where users can earn badges for certain things. Users can also become the mayor of a location, which is earned by someone who frequents a location more than anyone else.
How to Market Your Business with Foursquare – If you’re just starting out, trying to make a niche for yourself in town, Twitter and Facebook and any add-ons like Foursquare bring a new playground for trying things, for building some community fun, and for bringing added value to your customers and those fan/following them on all of the above. This article is a good common sense place to start.