Brain and Behavior, from Serendip http://serendip.brynmawr.edu/bb/
Interactive exhibits, forum, and links aimed at exploring the observational basis and significance of the assertion that the nervous system underlies all aspects of human behavior and experience.
COGPRINTS: Cognitive Sciences Eprint Archive http://cogprints.soton.ac.uk/
Cogprints makes preprints and reprints of papers in all areas of the cognitive sciences openly available on-line. Authors can deposit their work here, and all may freely read it. Directed by Stevan Harnad (best known as editor of Behavioral and Brain Sciences).
Encyclopedia of Cognitive Science http://www.cognitivescience.net/
Reference work (published 2003) from the publishers of the journal Nature. This site exists mainly to persuade you to buy the print encyclopedia, but also makes several sample entries available.