As of July 1, 2008 teens cannot use cell phones or text message while driving in California. SB 33 prohibits drivers under age 18 from using electronic devices (e.g., cell phones, pagers, laptops) while driving. Currently California law SB1613 (which goes into effect on 7/1/08) will require all drivers using a cell phone to use a hands-free device, but SB 33 stops this from applying to teens under age 18. Emergency calls to 911 are exceptions for all drivers.
I can't say this new law is likely to make a difference however - the fine for both is $20 for the first offense and $50 for repeat offenders - which is hardly a deterrent. Massachusetts is currently considering the same type of legislation, but their proposed penalties are a one year suspension of the license or learner's permit and a $250 fine.
Research shows that drivers who are distracted are more likely to have accidents and teens are four times more likely to be distracted by cell phone use. According to the Centers for Disease Control and Prevention (CDC), motor vehicle crashes are the leading cause of death for U.S. teens. There are currently 17 states with laws prohibiting cell phone use for teenage drivers.
I still think parents need to make it the law - no cell phone while driving. The best thing we can do as parents is to model not using our phones while driving. The Governor of CA currently enforces this rule with his own teenage daughter - cars and phones do not mix!