If you want to explore the... by Kai112DE
If you want to explore the city inch by inch, bring some time... I would say a week or so is fine, and if you come by car... PARK IT! Driving thru the city is already a challenge and a tough job on ur brakes (try Divisadero all the way between Lombard and Haight or Jones descending from Nob Hill, just to mention a few...), plus you will not have the frustrating task to find a parking lot ( i circled around Nob Hill for almost 90 minutes at a friday nite, i think i know the location of every hydrant within a 2 mile radius there...)
So use BART, MUNI, CALTRAIN or whatever, take a bus or streetcar, or walk (can be quite an excercise...)
Also be prepared to spent more money than expected... it is very tempting, plus SF is not really a bargain, but still... I found every $$$ was worth spending, so make sure you got plenty of those ;)