We have been to San Francisco many times over the past 20 years. One of the fun things to do is go on the cable cars.
We can remember from our first visit, when we still lived in England, the driver telling us "to get our butts in". We were standing on the outside of the car.
You can either buy a day, week, etc. pass or pay as you go. We bought a day pass for $11 each on our last visit. If you are buying individually each ride is $1.50.
We went from Powell Street to Fisherman's Wharf, which is the end of the line. After having a bite of lunch we got the cable car to Lombard Street. We wanted to walk and enjoy the zig zag street.
At the top of Lombard Street we caught a cable car and returned to our starting place. If we had known that it was only 3 rides we could have saved by buying single tickets.
However, we had so much fun being on the outside of the car. We had the thrill of going up those amazing roads and holding our breath coming down.
The only disappointment is, that the cable cars do not take you to all the places, you may wish to visit. If you don't take your car, you will be doing a lot of walking.