There are as many shopping opportunities in San Francisco as sight-seeing attractions. Each neighborhood has its own niche shops and boutiques. And of course, there are great shopping districts for every kind of taste.
Westfield Shopping Center: http://westfield.com/sanfrancisco/
Stonestown Galleria: http://www.stonestowngalleria.com/
Chestnut Street: http://www.chestnutshop.com/
Union Square: http://www.unionsquareshop.com/
Embarcadero Center: http://www.embarcaderocenter.com/ec/
Haight Street: http://www.haightshop.com/