I love the google maps app. I love the fact that I can see the urls, phone numbers and directions to and from a marker pin on the map. I was finally in an area yesterday where I could see the traffic. for those of you who haven't discovered that feature, navigate on the map to the location you want, and then hit the overlay icon in the lower right corner. Then Press traffic button. if it isn't available, the button text says something like "traffic information not available". When it is available you will see a red or yellow highlight on the roads where there are traffic.
Not as fancy as my gps but the data is cool and if they could write an app that lets us report traffic to the service from our iphone, how cool would that be.
Use two fingers to double tap the map to zoom out and one finger double tap to zoom in.
See this page for an explanation of what the map traffic colors mean.