The first Web site (1) from the National Center for Biotechnology Information offers a brief introduction to pharmacogenomics, a new science that "examines the inherited variations in genes that dictate drug response and explores the ways these variations can be used to predict whether a patient will have a good response to a drug, a bad response to a drug, or no response at all." This Web site defines pharmacogenomics as separate from pharmacogenetics, but explains that the two terms are used interchangeably in most cases. The second Web site contains an online brochure about pharmacogenomics from the National Institute of General Medical Sciences geared toward a general audience (2), and is also available in Spanish. To put the emerging field of pharmacogenomics in the overall context of genetics research, check out the next Web site from the Human Genome Project (3), which provides an overview of medical genetics. The next two Web sites contain in-depth articles about pharmacogenomics issues. The first, a cover story from Chemical and Engineering News (C&EN), delves into pharmacogenomics and the concept of personalized medicines, and also profiles some of the pharmaceutical and biotechnology companies active in this field (4). This site also includes links to related C&EN articles. The second article, from BioIT World, describes in detail how most pharmaceutical companies currently concentrate on weeding out potentially dangerous compounds rather than developing personalized drugs (5). Readers who would like to learn how the body metabolizes drugs (and thus gain a better understanding of what pharmacogenomics research addresses) should take advantage of the following Web site (6), also from the National Institute of General Medical Sciences. The next Web site contains an academic (but not scientifically obscure) article from PharmSci, a publication of the American Association of Pharmeceutical Scientists (7). The article, titled Pharmacogenomics: The Promise of Personalized Medicine, presents a comprehensive account of pharmacogenomic research, including historical perspective. Web links to PubMed documents for most of the article's references are provided. The last Web site, from the Nature Publishing Group, offers users a free online sample of The Pharmacogenomics Journal (8), published in 2003.