For as bad as the norwalk virus can be while experiencing it, it is over in a few days, though it can be serious I would be much more alarmed of any cases of the SARS (Severe Acute Respiratory Syndrome) on a cruise ship. In CHina 34 have died and in Toronto 3 have died and 1000's may have been affected. Hey, Toronto is only 90 miles from my home, another country but very close. I wouldn't stay home for fear of norwalk but would for SARS. These are diseases spread in close contact and not too many places to move to on a ship. Scary to have to think of these things, and risk is low at this time, let's hope it stays off low risk and off ships!