Facebook is entering the world of location-based marketing, similar to Gowalla, FourSquare, and Yelp, with Facebook Places. Facebook Places was recently launched in the US and is being deployed world wide.
Location Based Marketing, including services such as Four Square and Facebook Places is a fairly new addition to the Internet Marketing toolkit and has enormous potential for businesses, in particular businesses such as restaurants, coffee shops, bars and other "social" businesses where the general public gather.
A service like FourSquare is a fun web and mobile application that allows registered users to connect with friends and update their location. Points are awarded for "checking in" at venues.
Facebook Places, similarly, will allow users to let others know where they are. This video that was published on the Social Media Examiner page explains what Facebook Places is all about.