Should I refrigerate eggs?
The exterior coating on an egg is known as the "cuticle".  It helps to protect the (porous) shell and minimize moisture loss, but it eventually breaks down as the chick matures and prepares to hatch.

The reason that eggs in the US are typically sold under refrigeration is because they are washed with warm water and detergent to remove the large amount of bacteria that are deposited on the shell while being laid.  Once the cuticle is removed the egg becomes more porous.

Most bakeries that are using whole eggs will typically keep several flats out at all times to have them at room temperature.  Eggs will store better and longer in the refrigerator but if being used frequently and fairly quickly, they can also be left at room temperature.  Howard McGee in On Food &amp; Cooking says that egg quality deteriorates as much in one day at room temperature as it does four days under refrigeration.