Many countries, including the United States, Canada, European Union member states, and others, require that a comprehensive search for possible alternatives be completed before beginning some or all research involving animals. Completing comprehensive alternatives searches and keeping current with information associated with alternatives to animal testing is a challenge that will be made easier as people throughout the world gain access to the Internet and World Wide Web. Numerous Internet and World Wide Web resources are available to provide guidance and other information on in vitro and other alternatives to animal testing. A comprehensive Web site is Alternatives to Animal Testing on the Web (Altweb), which serves as an online clearinghouse for resources, information, and news about alternatives to animal testing. Examples of other important Web sites include the joint one for the (US) Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM) and the National Toxicology Program (NTP) Interagency Center for the Evaluation of Alternative Toxicological Methods (NICEATM) and the Norwegian Reference Centre for Laboratory Animal Science and Alternatives (The NORINA database). Internet mailing lists and online access to bulletin boards, discussion areas, newsletters, and journals are other ways to access and share information to stay current with alternatives to animal testing.