http://www.dmv.ca.gov/cellularphonelaws/index.htm here is the CA rundown...
of note, text messaging is still legal for adults, and no phone or texting under 18.
Astonishing...particularly considering that most people I know that do texting typically use both hands on the phone and are looking down at the phone's screen while they do it.
CHP OFFICER: Sir, I noticed that you were driving without any hands on your steering wheel and looking down at your lap while your vehicle was travelling at 70 mph. Would you be so kind as to provide an explanation?
MOTORIST: Officer, I was engaged in a legal activity.