Chromium

International Chromium Development Association
Basd in Paris, France the ICDA is a forum for every organisation that has any form of involvement with the world of Chromium.
Minor Metal Trade Association
Benefits and promotes the interests of its international membership, comprising companies actively involved in all aspects of the international trade of minor metals in all their various forms.
Chromium Central
Up-to-date information on Chromium for professionals and the general public.
Webelements
Basic Chromium Information (and a very silly chromium cartoon!)
Wikipedia
Open source infromation and discussion.
United States Geological Survey
Chromium Statistics and Information
Environmentalchemistry.com
Chemical, physical and historical information.
Agency for Toxic Substances and Disease Registry
Chromium Toxicity Information.
Elementis Chromium
Chromium Chemicals supplier. The website has lots of technical data about their products in PDF form.
U.S. Department of Labor Occupational Safety & Health Administration
Safety and Health issues rtelating to Hexavalent Chromium.