As healthcare institutions expand and vertically integrate, healthcare delivery is less constrained by geography, nationality, or even by institutional boundaries. As part of this trend, some aspects of the healthcare process are shifted from medical centers back into the home and communities. Telehealth applications intended for health promotion, social services, and other activities—for the healthy as well as for the ill—provide services outside clinical settings in homes, schools, libraries, and other governmental and community sites. Such developments include health information web sites, on-line support groups, automated telephone counseling, interactive health promotion programs, and electronic mail exchanges. Concomitant with these developments is the growth of consumer health informatics, in which individuals seeking medical care or information are able to find various health information resources that take advantage of new information technologies.