Stay safe during your road trip, and don't get distracted by your cell phone, PDA, Blackberry or even the GPS. You should NOT be texting, dialing, or any other kind of button-pushing while you are driving. You can change the radio station, but that's it.
This can be especially dangerous if you've already been driving for 8 hours straight, and in an unfamiliar area. Watch the road and concentrate on your driving at all times.
If you must use a GPS, do all the programming before you start your driving for the day. And try to let your passenger help you with the directions, so you don't have to keep watching the screen to see where you are going.