If you are looking for digital images to enhance your presentations, papers or web site look at the following two sites.
SXC,The Stock Exchange is a great source for digital images. SXC is a friendly community of photographers who generously offer their work to the public for free. It was launched in Feb. 2001 as an alternative to expensive stock photography. There are 199,167 photos online and more are added every day.The majority are copyright and permission free.
New York Public Library NYPL Digital Gallery is a free service from The New York Public Library offering hundreds of thousands of digital images of historical materials from the Research Libraries' original, rare and specialized holdings. NYPL provides free and open access to its Digital Gallery and images may be freely downloaded for personal, research and study purposes only. NYPL Digital Gallery provides access to over 450,000 images digitized from primary sources and printed rarities in the collections of The New York Public Library, including illuminated manuscripts, historical maps, vintage posters, rare prints and photographs, illustrated books, printed ephemera, and more.