In the 1936 film, "San Francisco" Jeannette MacDonald sings the film's title song, which of course includes the Gus Kahn-penned lyric "San Francisco, welcome me home again/I'm not at home to go roaming no more." For those who might be pining for Baghdad by the Bay (or for images from the infamous earthquake in 1906), this online collection from the San Francisco Public Library will be most welcome. All told, the San Francisco Historical Photograph Collection contains more than 250,000 photographs of San Francisco and California, although not all of these photographs are available online here. Visitors should begin their voyage through these images by using their search engine, which allows them to search by photographer, subject index, or by date. Perhaps the most novel way to search the images is to look through the photos by using an interactive map of the entire city. Here visitors can find photographs of the historic Moulin Rouge nightclub in the historic Barbary Coast area, or move on over to Sutro Heights over on the Pacific Ocean. For those who might be feeling a bit less adventurous, there are a number of thematic collections, including "Picture This: Family Photographs of Everyday San Francisco".