I don't keep them in cartons. I use 24 count mini muffin tins and stack them 3 tall. 72 eggs in less space than 36 in cartons. Just move them up as you take them, as this let's me play with all those gorgeous eggs!
I know who did what because I have a monitor pointing at them, and right now I'm watching Klessey our white Plymouth Rock give us a beautiful pinkish brown egg!
It is dual purpose, as it lets me know which eggs are the freshest for selling or consuming. They are also labled with a letter which corresponds to the name of the bird. Then they get charted by the day.