Check-in services have been one of the few Web 2.0 concepts to tightly combine location data with social media interactions, but it has not been clear if such services convey distinct local ranking benefit beyond the sort of citational reference provided by general online business directories….
In a move that seemed inevitable, Google Latitude announced the ability to check-in to places . Latitude is a 2-year-old service that has allowed people to share their location with others. However, until now, that location was simply a pinpoint (with photo) within Google Maps