You might be interested to read this, which is a brief summary of medical "phase of the moon is linked to X" studies, from alt.folklore.urban about ten years back; childbirth, suicide, hospital admissions, &c. Interestingly, about 40% of (medical? citations vague) people seem to believe in a lunar-phase correlation. Of course, 40% of people believing in a correlation means you might well expect to get slightly more psychosomatic illnesses at those times, just to mess it up a little... (The general medical-urban-legends archive, here, may also be of some interest to poke through) -AG.