If you go to San Francisco, be sure of...

be wearing flowers in your head? No, that's SO demode. If you go to San Francisco, actually, there are some things you will certainly do:
Go to Alcatraz
Go to Chinatown
Cross the Golden Gate
Go down Lombard Street (Herbie went down that street in The Love Bug, and the fact that I remember watching it projected from film, not from a computer, gives further support to my previous post)
Visit Pier 39 and Fisherman's Wharf

Howerver, there are a few other things really worth doing:
Going up the Coit Tower
Going to the Financial District
Walking under the falls in Vaillancourt Fountain (also called Quebec Libre!)
Going to the Muir Woods
Having a Shrimp dinner in Bubba Gump (it certainly takes some courage to make a Forrest Gump themed restaurant)

You know, Mama said San Francisco is like a box of chocolates; you never know what you are gonna get...