Society for Light Treatment and Biological Rhythms - http://www.websciences.org/sltbr/ A not-for-profit international organization founded in 1988 which aims to foster research, professional development and clinical applications in the fields of light therapy and biological rhythms.
Delayed Sleep Phase Syndrome - http://www.geocities.com/delayed_sleep/ Comprehensive site with symptoms, causes, treatments, and links to further information on DSPS and circadian rhythms.
Circadian Sleep Disorders Association - http://www.circadiandisorders.org/ Support and providing information to those affected by circadian sleep disorders such as Delayed Sleep Phase Syndrome. Includes links, FAQs, message board and a mailing list.
Scientists Find Eye Pigment Controls Circadian Rhythm - http://www.eurekalert.org/pub_releases/1998-11/UoNC-DECN-191198.php A brief report on an eye pigment, cryptochrome, which appears to control mammals' circadian rhythms.