The attorney general of the state of New York has gone after CVS and Rite-Aid for repeatedly selling expired goods on their shelves, including OTC medications. This has long been a problem in retail, but this is perhaps the first time that it has ever resulted in a lawsuit.

In 2005, Clark himself found OTC medications that were 5 years past their expiration dates on the shelf of a third chain drugstore. He was so fired up that he brought it to the manager's attention. Unfortunately, the manger was underwhelmed by Clark's complaint and didn't seem to care.

Recently while in a warehouse club, Clark discovered expired soft drinks on the shelf. He found an employee and showed them the items. But when he came back a week later, they were still there.

Clark doesn't believe there's any conspiracy to sell us spoiled food. But you must be your own police officer and check expiration dates before you make a purchase.

In fact, the penny-pinching guru describes himself as "obsessive compulsive" when it comes to checking dates. He routinely digs around on the shelves to get the latest possible date on milk and medications.

One caveat: It's difficult to tell if the date is a "marketing expiration date" or the real deal. Some drug makers put an early date on their products to get you to throw them out and buy more.