In addition to seeing where your Latitude buddies currently are on a map and sharing your location with them, you can now use the iPhone Latitude app [iTunes link] to check into places.
The app requires iOS 4 and above to work; iPhone 3GS, iPhone 4, iPod Touch and iPad are supported. Latitude will also automatically check you out when you leave if you set it to continuously update your location, but that feature doesn’t work with the iPod Touch.
Google has also translated its Google Places app [iTunes link] into 30 languages and added the ability to personalize your experience by saving places. To see the places you’ve saved or starred, tap on the new “Saved” icon on the app’s main screen.