The incredible California Palace of the Legion of Honor is free the first Saturday of the month for Bank of America Cardholders. Such a deal! [Goes without saying that you can always buy a ticket and go, too.]
We've found it best to get to museums in San Francisco earlier in the morning when crowds are less -- and yet there's an organ concert in the museum at 4:00.
So we'll stay at the museum till 12, have a picnic on the grounds [gorgeous scenery and views], rest our feet, and then set out on a 2-hour walk up and down the hills exploring the area. [Route TBD]. We'll return to the museum in time for the 4:00 concert and then head for home.
If you find that you prefer spending less time in a museum but would still enjoy the outing, just bring something to entertain yourself [book, phone] when you're done, or enjoy a walk through the surrounding neighborhood and meet up with the group for lunch and departure for home.