I don't know anything about distances/cities in the San Francisco area, but you might look through these.
For USJA clubs, go to here and sort. I didn't find ANY in San Francisco. [URL="http://www.usjamanagement.com/public/charteredClubs[/URL]
The Mits Kimura club looks to be pretty good from what I've read online. If it's closest, give it a try.
It's odd, not that many Judo clubs. But, Judo is a niche/minority sport/art in the USA anyway. So go figure.
I thought the same thing as the OP when I looked for Judo clubs in San Francisco a year ago. It's frustrating and mostly fruitless. SFJI is way, WAY out in Sunset Beach- doable, sure- but FAR. Mits Kimura is downtown, and looks great- but it's only two nights a week. And that's IT as far as Judo in San Francisco goes.
Cahill's is out by the airport- which is not at ALL in the City. Wonderful though I'm sure it is, location-wise, it's not close.
So basically: two places to do our sport in the entire city of San Francisco- only one of which is an actual proper Judo dojo.
Which is weird. And sucky.
Going to chime in here, even though it's a necropost (I've been dead for 5 years.)
I've just joined SFJI, and yes it's out in the Sunset but it's also right next to the L Muni. If you're starting at Embarcadero, that's only 30 minutes.
I'm not going to comment on the quality of the club because I've only been to one session, but it was fine. Drop me a message or check out my training log if you're looking at SFJI as a club and you've come across this post, and I'll give you some more up to date info.