Luna Commons is a database of sixteen free digital image collections built using Luna Imaging's Insight software. And there's a lot of cool stuff, well over a hundred thousand images all available for download in good resolution. Here are some of the collections featured: Pratt Institute Fashion Plate Collection, The Farber Gravestones Collection, Maps of Africa, Cornell Political Americana Collection and the The Estate Collection of art by HIV+ artists. The advanced search allows you to search across all collection, for example seeing everything across all collections about animals or New York or your birthyear. Whatever you look for, it's gonna bring up a boatload of interesting images.