Eastern Washington University Digital Collections
Otis W. Freeman Collection: "Dr. Otis W. Freeman (1889-1964) taught geology and geography at Eastern from 1924 through 1953. Dr. Freeman's photograph collection includes over 500 lantern slides, primarily images of the physical geography of the Pacific Northwest, which he used to illustrate his lectures." Along with the Freeman Collection EWU hosts some other noteworthy digital collections including Communities of the Inland Northwest and Pacific Railroad Survey Prints (worthy of a post in their own right!).
There are more and more excellent small digital collections like those at EWU becoming available as regional colleges and historical societies and even small town museums scan parts of their collections and make them available online. But how is one to find this material? What is needed is some kind of master index of primary source historical material available online. It used to be that if you were looking for online materials you went to the Library of Congress and a few other sites and you were done, but now so much more is available if only you can find it! The only way to organize such a growing and changing body of material would be to use a wiki, perhaps a page on Wikipedia itself.