There are many places where you can find Creative Commons licensed materials (e.g., Flickr's advanced search lets you filter by license, and all PLOS journal articles are Creative Commons licensed), but BoingBoing just linked to an amazing resource: Wellcome Images. This website, run by the Wellcome Trust, contains images depicting "two thousand years of human culture," and everything on it has been released under a Creative Commons license2.
Wellcome Images is one of the world's richest and most unique collections, with themes ranging from medical and social history to contemporary healthcare and biomedical science.I've only been browsing for a short while, but have already found a ton of images I think I'll use in my course. Who wouldn't want pictures of a malaria parasite in a mosquito's gut, an opium poppy, a human embryo implanting at 6 days, a picture of male bodybuilders pre-testosterone-injections, or drawings of morels? Go find some for yourself!
All our images are available on demand in digital form. Search online or use the expertise of our professional scientific and historical researchers.
Whether it's medicine or magic, the sacred or the profane, science or satire - you'll find more than you expect.
This unrivalled collection contains historical images from the Wellcome Library collections, Tibetan Buddhist paintings, ancient Sanskrit manuscripts written on palm leaves, beautifully illuminated Persian books and much more.
The Biomedical Collection holds over 40 000 high-quality images from the clinical and biomedical sciences. Selected from the UK's leading teaching hospitals and research institutions, it covers disease, surgery, general healthcare, sciences from genetics to neuroscience including the full range of imaging techniques. (quote from here)
1 As long as the educators are creating non-commercial works, and even then some Creative Commons licenses allow commercial works.
2 All images are either under a Creative Commons Attribution, Non-commercial Licence 2.0 or a Creative Commons Attribution, Non-Commercial, No Derivatives 2.0 license.