The fact is that expiration dates mean very little. Food starts to deteriorate from the moment it's harvested, butchered, or processed, but the rate at which it spoils depends less on time than on the conditions under which it's stored. Moisture and warmth are especially detrimental. A package of ground meat, say, will stay fresher longer if placed near the coldest part of a refrigerator (below 40 degrees Fahrenheit), than next to the heat-emitting light bulb. Besides, as University of Minnesota food scientist Ted Labuza explained to me, expiration dates address quality—optimum freshness—rather than safety and are extremely conservative. To account for all manner of consumer, manufacturers imagine how the laziest people with the most undesirable kitchens might store and handle their food, then test their products based on these criteria.
From the Upcoming ueue, submitted by KillerBee.
How long food is good has much more to do with how it's stored than the expiration dates. Eggs, for example, actually keep longer if you store them in a colder part of the fridge- the compartment in the door designed for egg cartons is too warm to keep them very long. Try StillTasty.com to take the guesswork out of how long food is REALLY good for, and to learn how to store it properly. It's incredibly useful.
One of my favorite things is discovering that the carton of milk I bought is still good, a week or two after the expiration date. Pathetic, right? ;)
I usually throw out the milk jug when the milk smells sour after being poured into a glass (there is always a bit around the jug mouth that makes it impossible to smell just by sniffing the top). I keep eggs for over a month, the older they are the easier they are to cook with. I usually buy them in bulk (waaay cheaper that way) and so they sit on the bottom shelf of the fridge, which in my case is right above the freezer.
anyway, I'm extremely conservative about my food. The power of suggestion and all.