The shelf life of eggs is pretty short and it's easy to waste a perfectly good batch. If you need to keep eggs for an extended period, the Preparedness Pro blog suggests you coat them in mineral oil.
While you certainly don't want to be doing this for every carton of eggs you get, it comes in handy if you end up with a bunch of extras. Preparedness Pro outlines the steps:
All you have to do is warm a quarter cup of mineral oil (just about 10 seconds in the microwave will do). Set your eggs outside of the carton (because it will be hard to get them out one you start using the mineral oil). Put on some food handling gloves (I buy this at one of the warehouses)... Dab a little bit of the warmed mineral oil on your hands and then pick up an egg. Run your oiled hands all over the eggs, making sure to cover it completely with the mineral oil. Don't worry if you're putting it on too thick or thin, just so long as every part of it is covered. When you're finished with an egg, put it in the egg carton, small pointed side down
When you're done, store your eggs in a cool, dry place. They should stay fresh for at least a few more weeks. Head over to Preparedness Pro for a few more tips on eggs preservation, as well as a followup post that adds a few more tricks to make the process easier.