Check out Google Earth

When I ordered our Prius, we decided on package #5 not thinking we could justify the additional $$$ for the package #6 with NAV. Since then, and having read numerous posts attesting to the benefits of this option, I have regretted not getting it. I have looked into after market additions but was not all that impressed and am really not ready to have someone tear up my dash board yet. I then looked into the various hand held and portable GPS units and again found it hard to justify the hefty price tag for some of these.
I eventually found the Microsoft Streets & Trips software with the GPS locator. This was a $129.00 program that installs on my laptop, with a small GPS receiver that has a usb connection, that you suction cup to your windshield while traveling. The program is really great, you can plan and route your trips, go online before you leave to update for any detours and while traveling the GPS locator shows you were you are and reroutes you if requested. It does not have voice directions. The map continually scrolls so you don't have to click on a side bar to get to the next map page, as with other map programs, it is basically the same as MSN's MapPoint with the ability to scroll.
Now to the point of this thread, if you enjoy maps online and you have yet to experience Google Maps, try it and you are in for a treat. The map details are fantastic and it includes satellite imagery. Yesterday, I was introduced to Goggle's newest mapping program, Google Earth, and was blown away. This was originally the Keystone program and has now been purchased by Google. It is interactive worldwide satellite imagery with mapping capabilities. If you are interested here is the link to install the free application: http://earth.google.com/. Make sure you check out the 3D and tilt function for some of the major cities.
I can visualize a not to distant future, in-car navigation system, utilizing similar graphics and software, along with GPS and wireless internet connections.