There is currently a bill before the California Legislature that would ban all plastic shopping bags and charge at least 5 cents for paper ones. That should get people to remember to bring their reusable bags to the store!
Of course, there is the issue of our needing garbage and recycling bags. We may have to start buying bags for those purposes, but it would all be worth it if people wouldn’t waste bags and our waterways etc. weren’t littered with them.
Here’s a great article on it from the SF Chronicle.