People

Bright Sparcs
A biographical, bibliographical and archival database of more than 3,000 Australian scientists with links to related articles and images.
http://www.asap.unimelb.edu.au/bsparcs/

Catalog of the Scientific Community in the 16th and 17th Centuries
A collection of 631 detailed biographies of scientists. Part of the Galileo project, and compiled by the late Richard S. Westfall. The collection is searchable, but there does not appear to be a contents page.
http://galileo.rice.edu/lib/catalog.html

The Imagination Symbol
Provides random links about the medieval philosopher and scientific pioneer Bishop Robert Grosseteste.
http://www.imagery-imagination.com/symbol.htm

People of Ideas (Philosophers, Scientists and Theologians)
Brief biographies of many key figures, from ancient Greece to the late 20th century. By Presbyterian minister Miles Hodges.
http://www.newgenevacenter.org/09_Biography/09b_Thinkers/09b_Thinkers.htm

Profiles in Science
Biographical information and archival collections of several prominent twentieth-century American biomedical scientists.
http://profiles.nlm.nih.gov/

SJSU Virtual Museum
Biographies from the history of mathematics, science, and technology.
http://www.sjsu.edu/depts/Museum/aamenu.html

World of Scientific Biography
Biographies for a large number of scientists categorised by discipline. Provided by Eric Weisstein.
http://www.treasure-troves.com/bios/bios.html