The National Highway Traffic Safety Administration reports that 80 percent of all traffic accidents occur within 3 seconds of the driver's inattention.
Now true, this might not always be your cell phone - you could be eating, drinking, fiddling with your music, putting on makeup or shaving. But apparently most states consider cell phone usage a major contributor to incidents, According to the Insurance Institute for Highway Safety, by July 1, 2008 seven states will have a ban on hand held cell phone usage - in two states it will be a secondary violation to add to a primary violation, but in five states it's the primary violation.
Some states also have restrictions on cell phone usage for drivers under 18 years old...and I will resist the urge to rant about text messaging while driving.