The wonderful shoreline park that used to be an airstrip and is now one of the best birdwatching sites in town: Crissy Field.
The Strybring Arboretum and Botanical Gardens in Golden Gate Park
The market in the Ferry Building
Fillmore Street, especially the hardware store.
SCRAPS or "Scroungers Center for Reusable Art Parts" (like the Twin Cities' Art Scraps ReUse store).