Peter here. I live in San Francisco and recently started bicycling again after several years of not. (Before moving to the Bay Area I lived in Bike Nirvana, a.k.a. Amsterdam.) I got a fairly cheap Specialized Secteur Sport on Craigslist and have been riding 30-40 miles a week... which isn't much, I know, but that will increase significantly throughout the fall/winter -- weather permitting.
Mostly I ride in GG Park, sometimes down to Lake Merced, sometimes up to the Presidio. I live on a fairly respectable hill, so I'm climbing a lot whether I want to or not.
Oh, and I'm doing the AIDS/LifeCycle next year.