Two months pass, it's the morning of event and now you've got 2 hours to pull together some imagery that will keep that first-year medical class interested and informed. Naturally, you turn to the Net for help. And fortunately, lots of online repositories of medical imagery and media are freely available. In many the quality of the images is poor, but a few sites are worth bookmarking.

The best is probably the Health on the Net (HON) Foundation's Medical Media Library. HON, based in Geneva, grew out of a 1995 conference on telemedicine. It has since developed a number of Internet initiatives involving health care, including this impressive online media database.

HONmedia contains more than 1950 medical images and videos covering 1200 themes and topics. Subjects range from anatomy to psychiatry, and this site isn't above injecting a bit of humour into its imagery, as shown by the short video Human macrophage ingesting candida albicans. The sound effects alone are worth the downloading effort.

Another place to turn is the University of California's Medical Imaging Library. This is a large database of teaching materials. It is not well organized but it does contain thousands of multimedia images and more than 700 health-science movies.

If you want to spend a few bucks, several professional graphics houses sell quality images on the Net; Blausen Medical Communications and the Medical Illustration Group are just 2 examples. A search for "medical images" in any search engine will turn up hundreds of results. You can also visit Yahoo's medical imagery directory.