Google just announced a new feature of its Latitude Android app which will definitely pose a grave threat to Foursquare and other location-based social networking app. Yes, folks – you can now check-in to places you’ve visited either manually or automatically. And to make the new feature different from the check-in service of other location-based social networking sites, Google has added some twists to their own check-in service. First of these is the ability to turn on check-in notifications via the Latitude app’s settings. Once turned on, you’ll receive notification to check in at a nearby place once you arrived there. You can also choose to check-in automatically at a particular place which you can designate. Finally, once you leave the place, you can set Latitude to check you out of that place. This means that you’re friends will know that you have already left that particular place. Now since Google Latitude and Google Maps Android apps are connected or to be exact, Latitude is built right into Google Maps for Android, this check-in feature works across these two Google Android apps. So, when you check-in to a particular place via Google Latitude Android app, you’ll also see your location or your friends location on Place page of that particular place as well as their markings on Google Maps. From there you can fire up Google Maps Navigation to get turn-by-turn directions to get to the place where they check-in. What good thing about this new check-in feature is the fact that it is an opt-in feature. You can choose to share any check-ins with your friends on Latitude publicly on the web and your Google profile or just keep your check-in activity to yourself. To get the check-in feature, you need to update Google Maps on your Android phone. And watch the video demo below as well.