When I bought my Prius, the first thing I did was install a Peripheral iPod input, which connects directly to my car stereo and allows me to control the iPod through the stereo and steering-wheel buttons.

Last weekend I plugged in the iPhone to my car stereo, and realized the iPhone features are great for driving. Some of the benefits are:
* it stops playing music to notify me of an incoming call (which is great, because there are times when I wouldn’t hear my phone ring in the car)
* i can use the speakerphone or a hands-free headset and not have to hold the phone while talking
* when i hangup a call, it automatically resumes playing where the song left off
* i can use Google Maps for directions (although without gps, but that isn’t that big of a deal)
* and i can watch YouTube videos while driving (just kidding ;)

The iPhone is already a great in-car audio and navigation tool, and with a few tweaks (gps, voice recognition, auxiliary device control), it could replace the need to have an in-car nav and stereo. Are GPS and stereo manufacturers now competing with Apple?