In 2001, the U.S. Postal Service issued a diabetes awareness stamp. According to Diabetes Monitor, the stamp was designed by artist James Steinberg. That same year, Dr. Lee J. Sanders published The Philatelic History of Diabetes: In Search of a Cure, a book which tells the history of diabetes through 30 international postage stamps. The book is available at Amazon.com for $14.95.
There is a lecture by Dr. Standers on the internet called From Thebes to Toronto and the 21st Century: An Incredible Journey. It gives a nice overview of this topic, along with pictures of a lot of lovely stamps. Dr. Sanders is a podiatrist at the VA Medical Center in Lebanon, Pennsylvania.
My favorite stamp is a 1999 Canadian stamp of Frederick G. Banting and Charles H. Best, the discoverers of insulin. Shortly after I was diagnosed with diabetes, I read The Discovery of Insulin by Michael Bliss. I was in graduate school at the time, and deeply involved in research myself, so the book was an eye-opener in terms of medical ethics, animal research, the real "messiness" of research that can be made to appear neat and clean after the fact, and (last but not least) professional rivalry. I would love to have this stamp, put it in a frame with a wide white mat, and hang it in my office.