I don't anymore either- I vote by mail.
And if I had my sample ballot with me, that was taken as an ID- name and address on the mailing label.
But when I showed up without the sample ballot I had to show driver's license.
Nothing I could find says that ID is required to vote in CA unless you are voting for the first time and left certain information off of your registration. If that is the case, there are over 30 acceptable forms of identifying yourself, including :
Driver license or state-issued ID card
Passport
Employee ID card
Credit or debit card
Military ID
Student ID
Health club ID
Insurance plan ID
a recent utility bill
bank statement
government check
government paycheck
document issued by a governmental agency
It looks very similar to how PA does it (ignoring its own new ID law which is in a sort of limbo). First time you vote at a given precinct, you need to bring either your voter registration card or some form of identification which can include things like a utility bill. After that, you sign the book they have, and from then on every time you vote, you just give them your name and sign the book; your signature is compared to the one you gave the last time you voted.
ETA:
My standard rant on the issue.... In person voter fraud in the form of showing up to vote as a different person, is exceedingly rare. So rare, it is for all practical purposes, non-existent. The reward is just too little for such a high risk. If there is going to be voter fraud at any significant amount, it's going to happen at a different level that voter ID is not going to help. If anything, we should be fixing voter registration to eliminate duplicates, deceased, and people who have moved away. I just see voter ID laws as a solution in search of a problem.
That said, I'm not inherently against requiring id when you vote. But if you must go that route, it needs to be something slowly introduced over the course of several elections (IMO presidential ones) and there must be a means of ensuring everyone can easily obtain acceptable ID for free.