While many Google Maps users may primarily use the app for getting around in their cars, Google’s been increasing the service’s utility over the past several years, adding support for alternate modes of transport, like plotting routes appropriate for pedestrians. Lately, it’s been gung-ho about integrating all sorts of mass transit information into the app. We recently saw additions like the complete route schedules for transit systems Google’s partnered with. Now that data is starting to get some serious use, with the introduction of navigation that supports mass transit.

With Google Maps 5.7, you can now integrate travel on mass transit systems into your directions for navigating any of the 400-odd cities for which Google has transit data. That means that you can hop on a bus and Google Maps will use your smartphone’s GPS to keep track of where you are on its route, notifying you when it’s time to get off or make a transfer. The only problem is getting a GPS signal, which will limit how practical the system is for subway users.

There’s also a new photo viewer for businesses that have added images to their Place pages, and Google has made it easier to access navigation aids when walking or driving with a quick tap on an icon. One of the cooler additions is a bit hidden away, relegated to Google Labs for now. If you enable it, though, you’ll be able to manually download map data to your smartphone, ensuring you’ll be able to find your way around even when you can’t get any reception. You can also review what areas you’ve cached, and delete unneeded data.

As always, you can get the new Google Maps in the Android Market.