Sorry for the delayed reponse; didn't see this until now.
There are many folks in the Bay Area doing interesting work in the area of health policy. Due to my personal experience (and political biases), I am more familiar with researchers advocating market-based reforms, rather than government-sponsored universal coverage type reforms. If that's what you're interested in, I'd be more than happy to give you some names ... let me know and I'll PM you.
PS. What about a policy degree? I think you can do an MPP at Berkeley ... which reminds me! You might love the Berkeley-USCF joint program ... my memory is that students in the JMP pursue a masters degree in some related field, like policy, while getting the MD (MA/MS/MPH/MPP from Berkeley and MD from UCSF but preclinical years are spent at Berkeley). Also, MD programs at Stanford and UCSF have agreements with Berkeley to send students for the MPH, just to make things simpler from the administrative (admissions) perspective.
The cure for anything is salt water: sweat, tears, or the sea. -- Isak Dinesen
I used to work as a PT in San francisco ~ 10 yrs ago prior to returning to australia and studying medicine here.
For Public Health info I could definitely recommend San Francisco General Hospital - as it deals with so many Public Health issues and also at a grass roots level out in community clinics as well. There would be many different staff members there who would be most approachable and good for information gathering to help you make some plans.
There are so many different ways you could 'help' in the area of your interest and not all require MD. Public health is definitely a good starting base and can then tie in with field work in heaps of different areas (professionally and geographically). I have a friend studying epidemiology in Cambridge and hear she is now doing a stint in Geneva at the UN. I know many others who spent many months last year in Banda Aceh following the tsunami. Others sit here and field calls from all over the state and organise responses for public health crises eg from meningococcal outbreaks to water contamination etc
There are even corporate 'for profit' organisations that I know of here in Australia that are implementing new healthcare systems in third world countries. These are much longer term projects than 'crisis' work such as that which many of the not for profits do and require research+++ obviously in many areas and involve a lot of planning with the local governments in those countries which they are addressing. Great to get involved in if you are free to travel! They also have a lot of non- clinical MD trained people in more of a corporate organisational role (another possibility for those out there tired of clinical work and looking for a change.)
So many opportunities abound. Good luck with your decision making and I highly recommend picking a few brains over at SFGH. (Just call their Public Health department and take it from there).