Facebook is adding a new tagging feature to its Open Graph that'll make it easy for Facebook users to tag their friends in any Facebook connected app. Called Mention Tagging, the new feature will scan text that is being typed into an app and look for phrases that mention the name of a user's Facebook friend.
Facebook describes how this feature could be used in an app like foursquare. Instead of directly tagging friends when they check-in, users will be able to enter the names of their friends in natural language. The Mention Tagging feature will pick up on a name and find that person in the user's Friends list. Whe
