Foursquare began nudging social networks out of the virtual world and into the real one when it launched its “location-awareness” service roughly a year ago. On Wednesday, Facebook pushed real-world social networking smack into the mainstream by unveiling a location awareness service of its own. The new service, called “Facebook Places,” allows Facebook members to check in via mobile devices when they arrive at a specific location — a restaurant, a store or any other venue. This lets their Facebook friends know where they are, and if any of them are nearby, they can join them.
