If so, Mat Honan has some expectation-adjusting advice for incoming residents.
If you're moving 3,000 (or even 300) miles to live in San Francisco; live in San Francisco. And by I don't simply mean that you should not live in the East Bay or the Peninsula or Marin. I mean live in a part of the city that your great-grandparents would recognize as being San Francisco. Somewhere that was entirely residential, and all of the homes in your neighborhood existed, prior to 1915. If you've only lived in SoMa, you haven't lived in San Francisco.
I'm not a fan of SF, but Mat does a nice job in highlighting the aspects of the city that are difficult to beat.
Update: Alex Payne has some advice for those moving to SF.
For a first world city, San Francisco is dirty. No, filthy. No, disgusting. Whenever I travel outside of San Francisco, I'm amazed at what a disastrous anomaly it is. Sidewalks are routinely covered in broken glass, trash, old food, and human excrement. The smell of urine is not uncommon, nor is the sight of homeless persons in varying states of dishevelment. I frequented tough neighborhoods in DC and Baltimore -- then the murder capital of the nation -- and only in San Francisco have I been actively threatened on the street.
Nailed it. Payne's points are exactly why I didn't like SF at all.