This Web site from the American Museum of Natural History (last mentioned in the October 4, 2002 NSDL Life Sciences Report) provides an introduction to microbes, covering the three major types -- bacteria, viruses, and protists (protozoa). The site contains very brief but colorful and effective descriptions of each type of microbe. The use of animation in the Size-O-Meter feature help relate the relative scale of microbes compared with us and with one another. Links to useful external Web sites are also provided. Although no lesson plans are provided, this site would be a useful addition to related classroom activities for younger students.