Well--what all are you looking for? Things to do with the children? your husband? yourself?
There was a group of east bay e-playans who were trying to get together a regular meeting at one of the cafes on Piedmont Avenue in Oakland. I didn't pay close attention, but I'll have a look for them. I think they were regional. Or you might find something at the Burning Man office in the City (get used to localspeak for San Francisco)--I'm sure there are lots of connections you can make there. Or try the San Francisco Cacophony sociaty--a lot of early burners came from them http://sf.cacophony.org/
I always thought the Museum of Children's Art at Jack London Square was pretty cool http://www.mocha.org/
You can combine a trip there with looking at the boats. Take a ferry ride to San Francisco--at night time it's almost like the playa a big dark space in a sea of light. (In baseball season you can take the ferry to and from night and weekend games--I hear that's really cool.)
There's also a non profit that gives art lessons to the developmentally disabled--I forget the name, but some of it is fantastic.
Lake Merrit is a periannual--just keep an eye out for wayward geese and homeless.
You can always check craigslist for classes and stuff http://www.craigslist.org/
You've got Chabot Obsevatory for planatarium. And if science stuff gets you definately check out the Exploratorium in San Francisco http://www.exploratorium.edu/
Both Chabot and Lawrence Hall of Science (in Berkeley) will do telescope viewings for eclipses and other astronomical phenonmena.
This has been sort of off the top of my head and with the fact of your children in mind. (Lots of this is stuff I loved as a kid.) If you give me a better idea of what you're looking for that may trigger more ideas.