Through
The Bay Citizen, I learned about the blog
Reel SF written by
CitySleuth who searches out the locations of classic Hollywood films that featured the San Francisco Bay Area as their locale. The blogger has done a great job of finding the locations and creating Then and Now comparison photos. Makes you want to do the same with some modern films like 1997's
The Game featuring Michael Douglas in some fantastic indoor and outdoor locations in San Francisco's Financial District.