I read on one of those University web sites (Minnesota?) that if you are putting eggs in your fridge or on the kitchen counter it is best to wash them first, since there might be salmonella on the shell.
They recommended washing the egg with water slightly warmer than the egg's temperature to prevent the problem byrandom mentions of opening the pores to bacteria. It seems counter-intuitive to me, since I think of pores as opening with warmth, but maybe egg pores are different than human skin. I use a little liquid Dial soap and warm water and dry the eggs before I put them into my fridge.
My chickens tend to get poo on their feet, and they lay the egg in a box where their feet were, so...
On the other hand, the other day I heard Melinda Lee say on her cooking show that only one egg in 10,000 will have salmonella, but I assume she is talking about commercially produced eggs, not ours.