A new laser technology will allow expiration dates and other information to be etched directly onto the shell of an egg. But that's not all: you can go to Egg Fusion's website, type in the code on the egg, and find out who produced it and when, how it was handled and shipped, USDA certification, pack date, sell date, expiration date, and much more.
On brown eggs, the laser etches through the brown outer layer to the white shell underneath. (Brown eggs are actually white--check the inside of the shell if you don't believe me--and just before the hen lays the egg, she adds a brown coating. On white eggs, she adds the coating too, but it's white. This is called the "bloom," or the cuticle. It protects the egg from bacteria.) If the egg is white, the laser is somehow adjusted to leave a brown mark.
If only you could find out the name of the hen who laid it. That's what I'm waiting for: I want my eggs to read, "Laid with love by Eleanor."