smell is the best natural way of telling when food is off (nature is good innit?). I agree that we are a bit nanny state over food - sell by dates and use by dates are always understated as the supermarket doesn't want to take any chances of being sued etc so i tend to add ignore these and use my own instincts about what is fresh and not fresh using sight and smell, anyway. Seafood is a bit different because of the type of bugs it attracts so you have to be careful about policing sell by dates, and once cooked it is still susceptible. At the end of the day though, the body is very good and has plenty defence mechanisms, including the old "open the sphincters and let the whole lot exit the body asap" (diarrhoea to you mate!) whereby the only thing to be wary of (except a toilet in the vicinity) is a plentiful supply of water to replace the fluid you're losing. I have often got up next morning and finished a prawn curry or chinese special fried rice that i half-ate the night before, and still live to tell the tale huck yuck yaaaarrrrghhhh................................................ (thud)