You can easily turn them into a cleaning agent. Grind the egg shells to a fine powder, then mix them with liquid soap or other cleaning product - thereby easily obtaining a wonderful abrasive cleaner.
An excellent use in the kitchen - break the egg shells into pieces and pour them down the drain. Gradually, the pieces will break apart into even smaller pieces and grind away any debris stuck to the walls of the pipes.
Egg shells can also be beneficial for your garden plants. Because they are so rich in calcium and minerals, they can nourish your plants - all you have to do is crumble them and add them to the soil.
Egg shells also make for great seedling containers. Make a hole in the egg and let it run out through it, then make the hole bigger. Put soil in it, place your plant seed. Once the plant grows big enough, plant it in the ground along with the egg shell.
If there's snails in your garden and you want to protect your plants from them - break apart the egg shells and sprinkle them around each plant.
Egg shells soaked in apple cider vinegar help against itching. Use the liquid only. It also helps against other skin irritations.
You can even use egg shells as Christmas tree decorations. Make a hole to pour the raw egg out of and simply decorate the shell - paint it, put stickers on, etc.
If you break the egg shells into medium-sized pieces you can make a puzzle for your child. Glue them to a suitable surface or item, then let your kid draw on them.
You can also make chalk for the kids with 1 tbsp flour and hot water. To them, add the ground to powder egg shells and leftover egg dyes. Shape it into a chalk and let it dry.
It's claimed that egg shells can be eaten and help against conditions such as osteoporosis. Get farm fresh eggs. Boil the egg shells 5 min., then air dry them and grind them to powder. According to some sources, it's enough to eat just 1/2 tsp of the ground shells daily.