So in retrospect, it would have been a terrific idea to buy a house in SF in mid-2009 and then sell it now. But if you followed Patrick's advice, there's no way you would even consider doing so. And bluntly, if you're a hacker, you probably should follow Patrick's advice. SF is the land of perma-renters.
Paying too much rent now and moving when the current bubble pops and/or sticking around long enough for the Ellis Act to make your apartment a bargain both seem like better strategies than speculating to me. Focus on what you're good at to pay the rent in the short term.
It's the people whose brains are wired into local and national real estate markets who stand a decent chance of knowing when to buy or sell, many, not all, of them realtors. Now if you can give people a better finger on the pulse of this market, go for it. Zillow, Trulia, and Redfin need not apply - their attempts at property valuations are wacko.