US health organizations reccomend to refrigerate eggs (they are more strict than other countries - so it doesn't mean eggs cannot be kept unrefrigerated for short periods of time until their expiration date, which is usually printed on the eggs/package):
1. Refrigerate Eggs
Take eggs straight home and store them immediately in the refrigerator set at 40°F (equal to 4 degrees celsius) or slightly below. Store them in the grocery carton in the coldest part of the refrigerator and not in the door.
2. Use Eggs Within Recommended Times
Use raw shell eggs within 3 to 5 weeks. Hardcooked eggs will keep refrigerated for 1 week. Use leftover yolks and whites within 4 days. If eggs crack on the way home from the store, break them into a clean container, cover it tightly, and keep refrigerated for use within 2 days.
3. Freeze Eggs for Longer Storage
Eggs should not be frozen in their shells. To freeze whole eggs, beat yolks and whites together. Egg whites can be frozen by themselves. Use frozen eggs within a year. If eggs freeze accidentally in their shells, keep them frozen until needed. Defrost them in the refrigerator. Discard any with cracked shells.
Some more links with data:
http://virtual.clemson.edu/groups/NIRC/pdf/Nourishing%20News%20September%202006.pdf
http://health.yahoo.com/topic/nutrition/foodsafety/qanda/mayoclinic/C07E922D-D163-4CC2-9D4C048B961C1DE5
http://www.masterstech-home.com/The_Kitchen/Articles/USDAEggSafetyRules.html