The HD2 has a digital compass app that has a guidance feature that integrates with Google Maps Mobile to help you find your way.
What you do is open the compass app, then hit "Set Destination." The program will then attempt to locate your position with GPS, and will bring up Google Maps. On the map, you can tap and hold where you want to go. Then, back in the compass app, you get a green dot. The idea is that you walk in the direction of the green dot to get to your destination. This is perfect for camping, or for street-level navigation in a city.