There are your standard GPS navigation units, and then there's the Dash. The Dash takes navigation to the next level, as it communicates two ways: back and forth from your car. That means you can search for stuff from your computer and then send it to your GPS setup in your car. No more punching in addresses via an annoying touchscreen, just send it from your email.
In addition, it has real-time traffic reporting, helping you avoid traffic jams whenever possible. It constantly updates traffic info from three sources: "traffic-information provider Inrix, used by other GPS navigators; the historical data from the Dash database, which even now is being gradually beefed up by beta testers all over the country; and your own personal Dash database, which learns your local bottlenecks as you drive." I'd like to see your regular GPS unit do that. Unfortunately, you'll pay dearly for the service, as the Dash is $600 and you'll pay $10 to $13 a month