The Essential Silicon Valley?
aristus: SF has a good community of geeks. DoloresLabs and NoiseBridge are at 83 Weise, near 16th street and Mission. And I host an open hacker house every Wednesday from 8am to 6pm: archivd.com/open-hacker-houseBut I would not try to schedule in too much if you only have a few days. Hang loose and see what comes up.