Do the Love tour of San Francisco in a hippy bus - painted VW camper van, they play great 60's/70'smusic and you get to drive down Lombard Street.
Go up the viewing tower in the De Young museum (you dont have to pay the entry fee to do this) - fantastic 360 degree views over the city as it is all glass at the top. Also go up Coit tower for a different 360 degree view point.
Ride on the old street cars along Fishermans Wharf - the F line. Farmers Market on a Sat is fabulous - lots of free samples, and cooking demos where you get to try a plateful of food.
Ride the cable car - go first thing in the morning so you dont have to queue and get on at Powell turntable and take the Powell- Hyde line over to Fishermans Wharf. The Grip Men who operate the cable cars are great characters!
Ocean Beach is fabulous - miles of sand, surfers, and BBQ foodtrucks, pelicans etc
Glacier Point at Yosemite is a must, also the Mariposa Grove to see the giant sequoias, plus lots of wildlife - chipmunks, deer etc
Whilst waiting for the whale watching boat at Monterey watch out for the sea otters swimming around in the harbour
Venice Beach - go behind the main street to find all the quirky houses built along the canals