A surprising number of digital images exist that document the Cornell University experience. Here are some traditional image resources and other digital resources that contain images.
The most significant resource for historic images of Cornell is Cornell's University Archives, housed in the Division of Rare and Manuscript Collections in Kroch Library. Quite a few of those images have been digitized and added the online collection:
Campus artifacts, art & memorabilia includes about 2000 plaques, pictures, sculptures, and other objects of artistic and historical interest located on the Cornell campus. It is based on the 1984 book "Contributions to Cornell History: Portraits and Memorabilia."
Ezra Cornell Papers: accounts, broadsides, correspondence, estimates, memoranda, maps, newspaper clippings, and other papers relating to Ezra Cornell, held in the Cornell University Library, Division of Rare and Manuscripts.
flickr contains thousands of images of Cornell (the campus and events like Dragon Day).
Many other college and university newspapers have digitized their collections. Check American Historical Newspapers Online for others.
Cornell Alumni Magazine on eCommons. Tip: enter search terms in a Google search and add the phrase (in quotation marks) "Cornell Alumni Magazine"