I don't know if you've tried it yet, but I found Uber to be great in San Francisco. They're cheaper than cabs, and they can pick you up where you are. This is as long as you have data or wifi active. I'm also flabbergasted that I managed to miss that museum in the Presidio the last time I went there - guess I'll have to go back and make a MR out of it too.
Terrific report! SF is an awesome place to visit.