I am all about re purposing items. For one, it helps with not bringing MORE items into a space. Take Egg Cartons for instance. Some farmers markets will let you bring in empty egg cartons to refill with eggs.
Another use for egg cartons is for storage! You can use them to store office supplies like paper clips, rubber bands, staples, etc. They can be a great jewelry organizer, especially earrings and rings.
You can use them to hold paint or other crafting supplies when the kids are working on school projects.
Basically cut off the top part and use the bottom half for storage and organization.