Here’s the CA DMV FAQ on the new law; don’t forget about it; it starts
tomorrow!

https://www.dmv.ca.gov/cellularphonelaws/index.htm

One key thing to note (that was of interest to me) is that while using the
speakerphone, and dialing/txt’ing while driving are not *specifcally*
forbidden, they are strongly discouraged, and an officer *can* pull you over
if he thinks you’re being unsafe while driving (and probably will as this is
another source of revenue for them), so be aware of that and be careful!