Google Navigation is an extension to Google Maps which turns the mapping capability into a true GPS killer by providing a third person isometric perspective.  What does this mean?.... Originally Google Maps was (and is) a great application as it replicated an electronic map with the enhancements of satellite imagery and global positioning to show the current phone location.  However, the detractor is that the viewpoint was only top down and the brain had to interpret to map which can be very confusing when travelling south and needing to take a turn east - the map looks like this is a right turn as the map always had north at the top of the screen when in fact it is a left turn.  By providing a third person isometric perspective, the map rotates according to the direction of travel.  Therefore, when heading south, an east turn will be left on the map as it should be - this is the way hardware GPS devices purchased at the electronics store work.

The best part - it's free, free, free!!!  No longer do you have to purchase a hardware GPS and subscribe to costly map updates.

The downside - the voice presentation is choppy and re-direction updates take awhile - that's the difference between hardware computing of a fixed purpose device versus software computing on a multi-purpose device such as an Android phone.