I've never heard of Compass before this, but it sounds pretty sick:

http://pogue.blogs.nytimes.com/2012/09/27/what-makes-googles-maps-so-good/

On this call, Google pointed out a new feature that I hadn’t seen before: compass mode. On an Android phone, you can call up a location like Trafalgar Square in London. You hold the phone in front of you to see a Street View-like photo of the scene — and as you look left, right, up, down, or behind you, the view changes, as though you’re looking through a magic window at another place in the world. You can even use Compass mode to look around inside places — I tried Delfina, the San Francisco restaurant — to get a feel of the décor before you go there.



Looks like Pogue is going to do a piece on Nokia's mapping system next.