I snapped this shot 48 minutes outside of Holland, Michigan last week. That’s my Sprint Evo Android phone being used as a GPS, being powered by a power inverter sitting on the floor, and plugged into the stereo’s auxiliary jack of my rental car. That’s how I roll on the road these days. The podcasts I download through CarCast are much more interesting than the radio, and the phone is smart enough to interrupt the podcasts to speak turning directions when necessary. If I’m looking for tunes, I stream Pandora stations. It’s also possible to stream YouTube videos, but I wouldn’t recommend doing that while driving.
But the key to making this work is the Kensington windshield mount. Without that, I’d spend time looking at my phone in my lap, which is outside my peripheral vision of the windshield.
If you’re using your phone as a GPS, I highly recommend picking one of these up. It will work on any common iPhone-ish shaped device. They also have an air-vent attachment model, which I do not recommend for travel (too tough to get on/off the vent) but could be a good choice for your own car because it may be a bit more discrete than having a suction cup on your windshield (better not to give thieves a reason to break in).