If you are more interested in the economical aspect, or you're an entrepreneur who wants to move to SF, this is how me and my co-founders lived with 1.1k/month in San Francisco, including the rent.
Rents are more expensive now, but you can still find workarounds. At the time I remember we didn't have lots of comforts (if any!) but we were happy with it. We landed in SF from Italy, and had to survive somehow while living the dream.
I don't suggest doing this for a long period of time though, except if you're happy and really don't care. Personally, I didn't.
http://www.quora.com/How-do-you-live-comfortably-on-a-40k-sa...
Rents are more expensive now, but you can still find workarounds. At the time I remember we didn't have lots of comforts (if any!) but we were happy with it. We landed in SF from Italy, and had to survive somehow while living the dream.
I don't suggest doing this for a long period of time though, except if you're happy and really don't care. Personally, I didn't.