Here's a question from timid Californians(!): My wife has expressed concern about the safety of eating raw shellfish--oysters and the like (yes we eat sushi, don't ask for rationality here, though I did once get food poisoning from it!). So we don't miss out on the experience when we come there in a few days--is there a way to tell the good oysters from the bad and the ugly, healthwise? Something we should be watching for? Thanks.