In an announcement on its website, Facebook said the feature would be available on its mobile pages for more than 20,000 OpenTable restaurant customers across North America. It wasn't immediately clear if Facebook would receive any commission from OpenTable bookings. Facebook engineers had developed this as a hack inside the company and a lot of people have been using it internally (at Facebook) with a lot of success. This is also yet another sign of the growing importance of local commerce - everyone from Google to Yelp to GroupOn wants a slice of it. Get the full story at GigaOM and AllFacebook