A rather ominous view of 555 California, taken from some other building. It's the tallest in San Francisco.
When I'm on the long board, I'll only come here a few times a week, which is just as well, because it's a bitch to get past their security. Not only do you have to show ID, but the company your visiting has to be called before you can head up. After the security pass is printed out you have to show it to one of the other guards by the elevator banks who will then check your bag.
555 Cal is one of the very few building with a security system that actually might do something though. Almost all downtown buildings have guards and require some sort of signing-in but I can't fathom how 95% of theses setups could actually be making the building more secure.
I was talking to a guard about this a few months ago and he told me the main purpose of the sign in sheet is to know who's in the building in case of a fire, which I guess makes sense. But overall, I hate wasting even 10 seconds signing in. Being waived up by a guard is a great feeling.