http://www.dmv.ca.gov/cellularphonelaws/
and has outlawed the use of handheld wireless telephones while driving as of July 1, 2008.
However, people still routinely ignore these laws. I still see motorists "on the phone" who are texting while holding the phone in their laps, or have the phone on speaker while holding it away from the head like it's a pack of playing cards.
There's also a certain group of motorists--who are also often driving SUVs with tinted windows and no license plates (at least none in the back)--who still talk on the hand-held cell phone quite blithely, with no concern at all.
I fear driving these days. Heck, I even fear being a pedestrian!
PHoenix has outlawed texting also.