webOS users are already used to having their Facebook contacts linked to their phonebook, but now it looks like iPhone users might be getting that feature in the upcoming iPhone OS 4.0 too. Folks who have been busy digging through the iPhone OS 4.0 SDK have found hints ofnative Facebook integration built into the phone. There isn’t much information as to what the feature actually does at the moment, but the most likely possibility is that it will link your Facebook contacts with your contacts in the Phone. It’s worth noting that the official iPhone Facebook app already allows photo syncing with contacts, but we don’t mind integration either. After the recent iPhone 4G leak, most folks believe that the upcoming iPhone 4G will come standard with the iPhone OS 4.0.